Ceglia v. Zuckerberg et al

Filing 238

DECLARATION signed by Peter V. Tytell re 237 Response in Opposition to Motion,,,, filed by Mark Elliot Zuckerberg, Facebook, Inc. filed by Mark Elliot Zuckerberg, Facebook, Inc.. (Attachments: # 1 Exhibit A, # 2 Exhibit B, # 3 Exhibit C, # 4 Exhibit D, # 5 Exhibit E, # 6 Exhibit F, # 7 Exhibit G)(Snyder, Orin)

EXHIBIT E

Designation: E1422 – 05

Standard Guide for

Test Methods for Forensic Writing Ink Comparison1
This standard is issued under the fixed designation E1422; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.

INTRODUCTION

This guide is intended to be a general guide for forensic ink examinations, both for the experienced
document examiner (Guide E444) and for forensic ink comparison specialists. The aim is to include
those techniques that will provide the most information about an ink with the least damage to the
document. Therefore, this guide refers to well-reported and thoroughly tested techniques currently in
use by document examiners in general practice and dedicated forensic ink comparison facilities.
By following the procedures outlined here, an examiner can accurately discriminate ink formulas
and reduce the possibility of false matches of ink samples from different sources or incorrect
differentiation of ink samples with a common origin.
1. Scope
1.1 This guide is intended to assist forensic examiners
comparing writing or marking inks. Included in this analysis
scheme are the necessary tools and techniques available to
reach conclusions as to the common or different origin of two
samples of ink.
1.2 Identifying ink formulas as to their manufacturer or time
of manufacture as well as performing ink dating examinations
are beyond the scope of this guide.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:2
D1535 Practice for Specifying Color by the Munsell System
E131 Terminology Relating to Molecular Spectroscopy
E284 Terminology of Appearance
E444 Guide for Scope of Work of Forensic Document
Examiners
2.2 NIST Standards:
1
This guide is under the jurisdiction of ASTM Committee E30 on Forensic
Sciences and is the direct responsibility of Subcommittee E30.02 on Questioned
Documents.
Current edition approved Dec. 1, 2005 Published January 2006. Originally
approved in 1991. Last previous edition approved in 2001 as E1422 – 01. DOI:
10.1520/E1422-05.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.

NBS Standard Sample No. 2106 ISCC-NBS Centroid Color
Charts3
NBS Special Pub. 440 Color: Universal Language and
Dictionary of Names3
3. Terminology
3.1 Definitions:
3.1.1 batch to batch variation—within an ink formulation,
difference in the concentration of a component of an ink
formula due to deviations during production that are within the
manufacturer’s tolerance limit.
3.1.2 chromatography—a method of separating substances
that is widely used in analytical and preparative chemistry. It
involves the flow of a liquid or gas mobile phase over a solid
or liquid stationary phase. As the mobile phase flows past the
stationary phase, a solute will undergo repeated adsorption and
desorption and move along at a rate depending, among other
factors, on its ratio of distribution between two phases. If their
distribution ratios are sufficiently different, components of a
mixture will migrate at different rates and produce a characteristic pattern (chromatogram).
3.1.3 fluorescence—a process by which radiant flux of
certain wavelengths is absorbed and reradiated nonthermally at
other, usually longer, wavelengths.
(E284)
3.1.4 infrared (IR)—referring to radiant flux having wavelengths longer than the wavelengths of light, usually wavelengths from about 760 nm to about 3 mm.
(E284)
3.1.5 light—electromagnetic radiant energy that is visually
detectable by the normal human observer, radiant energy

3
Available from U.S. Department of Commerce, National Bureau of Standard
Reference Materials, R. B311, Chemistry Building, Gaithersburg, MD 20899.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

Copyright by ASTM Int'l (all rights reserved); Tue Nov 22 12:31:55 EST 2011
1
Downloaded/printed by
Amanda M. Aycock (Gibson, Dunn & Crutcher LLP) pursuant to License Agreement. No further reproductions authorized.

E1422 – 05
having wavelengths from about 380 nm to about 780 nm.
(E284)
3.1.6 luminescence—the emission of radiant energy during
a transition from an excited electronic state of an atom,
molecule or ion to a lower electronic state.
(E131)
3.1.7 metamers—specimens differing in spectral reflectance
but having colors that match in light of one spectral composition, when viewed by one observer, but may not match in light
of other spectral compositions, or when viewed by another
observer.
(E284)
3.1.8 spectroscopy—in the most general sense spectroscopy
is the study of the absorption or emission of electromagnetic
energy by a chemical species as a function of the energy
incident upon that species.
3.1.9 source—an object that produces light or other radiant
flux.
(E284)
3.1.10 ultraviolet (UV)—referring to radiant flux having
wavelengths shorter than the wavelengths of light, usually
wavelengths from about 10 nm to 380 nm.
3.1.10.1 Discussion—Long-wave UV usually refers to the
spectral range of UV-A, with wavelengths from about 315 nm
to 380 nm. Short wave UV usually refers to the spectral range
of UV-C, with wavelengths from about 100 nm to 280 nm.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 ballpoint pen ink—writing or marking media intended
for use in a ball point pen. Typically, a thick, high viscosity ink
with an oil, glycol or rubber base.
3.2.2 dichroic filter—a filter with two transmission bands.
These bands are usually widely separated, and can be of
significantly different size.
3.2.3 gel pen ink—writing or marking media intended for
use in a “gel-type” roller pen. Gel pen inks constitute a unique
class of non-ballpoint pen inks. Typically, gel pen ink is an
aqueous ink of high viscosity, capable of maintaining a stable
dispersed or dissolved state of the coloring material even after
a prolonged period and exhibiting high fluidity under a
shearing force. The ink contains a coloring material (pigment
or dyes), acid-modified heteropolysaccharide and aqueous
medium (water and water-soluble organic solvent), in which
water constitutes at least 50 % by weight. Due to the incorporation of pigments into these formulations, the procedures
outlined in this guide for TLC evaluations will be of limited
value.
3.2.4 infrared luminescence (IRL)—the emission of radiant
energy during a transition from an excited electronic state of an
atom, molecule or ion to a lower electronic state (fluorescence
or phosphorescence, or both), where the spectrum of the
excitation source is in the ultraviolet (UV) or visible region of
the electromagnetic spectrum, or both, and the spectrum of the
emitted energy is in the far red or infrared (IR) region of the
electromagnetic spectrum.
3.2.5 ink formula—a precise recipe or set of ingredients and
their quantities that the manufacturer specifies for the final ink
product. These ingredients are colorants (dyes and pigments)
and vehicle components (volatile solvents, resins, etc.).
3.2.6 match between ink samples—the inability to distinguish between ink samples at a given level of analysis.

3.2.7 non-ballpoint pen ink—writing or marking media
intended for use in a writing or marking instrument other than
a ballpoint pen, including a dip or fountain pen, porous point
pen, roller pen, marking instrument, etc. Typically, a thin, low
viscosity ink with a water or solvent base.
4. Significance and Use
4.1 Ink comparisons are usually performed to answer four
basic categories of question: (1) whether an ink is the same (in
formula) as that on other parts of the same document or on
other documents; (2) whether two writings with similar ink
have a common origin, that is, the same writing instrument or
ink well; (3) whether the ink of entries dated over a period of
time is consistent with that dating or indicates preparation at
one time; (4) whether ink is as old as it purports to be (1).4
4.2 The procedures set forth in this guide are directly
applicable to giving a full answer to only the first of these four
questions.
4.3 With regard to the second question, differentiation of
formula (question one) would indicate a negative answer to this
question, as would differentiation with any of the additional
methods listed in Section 3. When dealing with contemporary
inks, however, a match of ink samples involving agreement in
all observable aspects of all the techniques considered in this
guide, while consistent with common origin, would not be
sufficient to support a definite opinion of common origin (2).
Contemporary ink rarely has sufficient individuality to support
a determination of common origin at less than the manufacturing batch level.
NOTE 1—Contemporary mass-produced inks are usually distributed as
a component in a complete writing instrument or in a cartridge. With such
packaging the ink is not subject to the mixing of inks and exposure to
environmental contamination that could individualize ink from a given ink
well at a specific point in time (1, 3). This sort of analysis, potentially
useful in the examination of older documents or those prepared under
certain circumstances, is beyond the scope of this guide, as is examination
of the ink line to individualize the writing instrument that produced it
based on its performance characteristics.

4.4 As to the third and fourth questions involving the age of
ink, dating techniques for determining either the relative age of
ink samples (from the same or different documents) or the
absolute amount of time since the writing of an ink line are also
beyond the scope of this guide.
4.5 However, regarding question three, it may be of great
importance in a forensic situation involving writing dated over
a period of time to determine that one or more than one ink
formula is present, that the use of various ink formulas fits a
pattern, that a particular ink formula matches samples of a
known date, etc.
4.6 As to the last question, a limit as to the possible age of
an ink entry can be inferred by establishing the date of first
production of the ink formula. Although beyond the scope of
this guide, identifying ink formulas as to their manufacturer or
time of manufacture utilizes many of the analytical procedures
described here. Specialized knowledge and experience on the

4
The boldface numbers in parenthesis refer to the list of references at the end of
this guide.

Copyright by ASTM Int'l (all rights reserved); Tue Nov 22 12:31:55 EST 2011
2
Downloaded/printed by
Amanda M. Aycock (Gibson, Dunn & Crutcher LLP) pursuant to License Agreement. No further reproductions authorized.

E1422 – 05
part of the examiner, as well as access to a collection or library
of ink reference samples is also required.
4.6.1 Such an ink library consists of samples of ink formulas
from known sources, usually manufacturers of ink, or writing
or marking instruments, or a combination thereof. The ink
reference samples are usually cataloged, analyzed, and stored
according to the methods described in Refs (2, 4, 5, 6) . Even
with access to a comprehensive collection, association of an
unknown ink sample with a single known formula is not
always possible. This is because some ink formulas are not
distinguishable, however, in most cases the analytical procedures outlined here are sufficiently discriminating that formulas
are distinguishable.
4.7 Comparison of ink samples by analysts without an ink
library can still provide valuable information. However, added
significance can be given to the meaning of a match if the
relative rarity or commonness of the ink formula is known.
Familiarity with or access to a comprehensive reference
collection of inks is useful for this purpose.
4.8 In expressing conclusions it should be remembered that
a match indicates that the ink samples are of the same formula
or of two similar formulas with the same nonvolatile components. The possibility that other analytical techniques might be
able to differentiate them should always be considered (2).
4.8.1 Therefore, conclusions in this situation should never
indicate that two ink samples are “identical” or “the same ink,”
but must be limited to statements indicating “inability to
distinguish the ink samples at this level of analysis” or
“exhaustive chemical and physical testing failed to detect any
differences between the ink samples” (2).
5. Interferences
5.1 Most interferences with ink examinations come from
variables that interact with the ink. These can be part of the
writing process, such as blotting wet ink (1, 2), or variations in
the paper (7), or various forms of contamination on the
document (7, 8), or a combination thereof. Simple precautions
can usually avoid problems.
5.2 Note and record any differences in the substrate, such as
the use of different paper for different documents or pages of a
multipage document. Also note and record variations in the
document, such as a signature written over a photograph on an
identity document, multicolored paper with different dyes or
colors of underprinting, intersections with printed or typed
material, etc. (7, 8).
5.3 The results of prior handling or testing should also be
noted and recorded. These effects can include discoloration or
fading from ageing, exposure to light or heat, as well as stains
from food or drink, dirt or grease, cellophane or other tape,
adhesives, perspiration or finger smudges, water, or chemicals,
including ninhydrin or other reagents for visualizing latent
friction ridge impressions, etc. (7, 8, 9).
5.4 In optical examinations care should be taken to consider
the potential effects of these variables (7, 8). In chemical
analyses paper blanks should be run as controls for these
variables (4, 5).

6. Reagents and Equipment
NOTE 2—It is important that all reagents are uncontaminated.

6.1 Purity of Reagents—Reagent Grade.
6.2 Purity of Water—Distilled or equivalent.
6.3 Reagents for Spot Testing, Solubility Testing, and TLC
Extraction Solvents:
6.3.1 Pyridine.
6.3.2 Ethanol.
6.3.3 Water.
6.3.4 Other reagents as required by Refs (1, 3, 23).
6.4 Reagents for Thin Layer Chromatography (TLC) Developing Solvents:
6.4.1 Solvent System I—Ethyl acetate, ethanol, water
(70 + 35 + 30).
6.4.2 Solvent System II—N-butanol, ethanol, water
(50 + 10 + 15).
6.5 Other ink extracting solvents and developing solvents in
accordance with Refs (5, 6, 10).
6.6 Equipment for Optical Examinations:
6.6.1 Stereomicroscope:
NOTE 3—Five to one hundred power total magnification is a range that
has been found useful.

6.6.2 UV Lamps or View Box, with both long-wave UV and
short-wave UV lamps.
6.6.3 Colored Filters, (gelatin, colored glass, interference
filters) as needed for visual and photographic differentiation of
inks.
6.6.4 Dichroic Filters, See Ref (11).
6.6.5 Photographic or other imaging equipment with appropriate film or other sensor, lighting, and filters for differentiation of ink samples.
6.6.6 Photographic or other imaging equipment with appropriate film or other sensor, lighting, and filters for recording
reflected infrared (RIR) and infrared luminescence (IRL).
6.6.7 IR image conversion device or system with appropriate light sources and filters for use in RIR and IRL modes as
well as appropriate photographic or other imaging equipment,
computer hardware and software for image acquisition or
processing, or both.
6.6.8 Barrier Filters for RIR and IRL—Long pass filters,
preferably sharp cut, that block visible flux. Suitable gelatin,
colored glass, and interference filters are commercially available (12, 13, 14).
NOTE 4—Since ink reactions can vary, it is advisable to use a series of
filters with cut on wavelengths from the red through the IR range of the
film or detector.

6.6.9 Excitation Source for IRL—Sources include: a continuous spectrum lamp with a filter to eliminate flux in the IR
and far red region of the spectrum, for example, a 10 % to 15 %
solution of copper sulfate in a cell with a 1 cm to 3 cm light
path, or appropriate colored glass or interference filters; or
lasers or other monochromatic sources.
NOTE 5—A variety of sources with different spectral distributions or a
variety of filters on a continuous spectrum source may be helpful in
discriminating ink samples.
When using a filtered source it is advisable to use a heat absorbing filter
between the source and the filter. This both protects the filter (15) and

Copyright by ASTM Int'l (all rights reserved); Tue Nov 22 12:31:55 EST 2011
3
Downloaded/printed by
Amanda M. Aycock (Gibson, Dunn & Crutcher LLP) pursuant to License Agreement. No further reproductions authorized.

E1422 – 05
eliminates a significant portion of the undesirable IR flux.

6.6.10 Photographic or other imaging equipment for recording observations as required.
6.7 Equipment for Spot Testing, Solubility Testing, and
TLC—It is important that all equipment is uncontaminated.
6.7.1 Stereomicroscope (See Note 2).
6.7.2 Hypodermic Needle, with an approximately 20 gage
hollow boring point or blunted point, scalpel or similar
sampling device.
6.7.3 Disposable Vial or Transparent Sample Container—1
dram or smaller suggested.
6.7.4 Disposable Micropipettes—10 µL or smaller suggested.
6.7.5 Precoated Plastic or Glass Sheets/Plates of Silica Gel,
without fluorescent indicator (60 Å pore size5 ).
NOTE 6—It is recommended that the TLC sheets/plates be kept in a
desiccator.

6.7.6 Glass Developing Tank with Air Tight Cover—This
tank should be the appropriate size for the sheet/plate being
developed.
6.7.7 UV Lamps or View Box, with both long-wave UV and
short-wave UV lamps.
6.8 Appropriate equipment for the additional methods listed
in Section 8.
6.9 All equipment and apparatus shall be properly maintained and calibrated.
7. Procedure
NONDESTRUCTIVE OPTICAL EXAMINATIONS
7.1 Light Examination:
7.1.1 Determine the Class of Ink—Under ambient lighting
conditions (natural or artificial), with or without the aid of
magnification as required, determine whether the class of the
ink is ballpoint pen or non-ballpoint pen (6). Observe the
overall appearance of the writing. Note and record anything
that might provide information about the kind of writing or
marking instrument used. For example, if there is an indentation down a central track, then the writing instrument may be
a ballpoint pen or rolling ball marker. Double indentations may
indicate a bifurcated nib dip pen or fountain pen. This step may
be performed with the use of reference standards prepared with
various classes of writing instruments on different substrata.
7.1.2 Determine the Condition of the Ink and the Overall
Appearance of the Writing—Note and record the presence of
anything that might have induced a change in the ink as
described in Section 2; for example, stains, burns, aging,
blotting, fading, attempts at mechanical erasure or chemical
eradication, discolorations, etc.
7.1.3 Determine the Color of the Ink—Inks that are metamers can sometimes be differentiated by the use of illuminants
with varying color temperatures or spectral characteristics, as
well as by narrow band or laser illumination. Various filters can
also be used for direct viewing, photography, or electronic

5
Merck Silica Gel, Whatman PE SIL G, and Merck HPTLC Silica Gel 60 have
been found satisfactory.

viewing, including wide and narrow band, short and long pass,
and dichroic filters (1, 6, 11, 16).
NOTE 7—The use of standard color notation may be helpful in
recording these observations. (NBS Standard Sample No. 2106, NBS
Special Pub. 440)

7.1.4 Microspectrophotometry (17) can be useful in differentiating inks by measuring their wavelengths of maximum
transmission or reflectance spectra, or both.
7.2 Ultraviolet (UV) Examination:
7.2.1 Observe the ink sample under both long-wave UV and
short-wave UV sources. Note and record the fluorescence
characteristics of the ink as well as the emission of any
fluorescence (18). (See Note 7.)
NOTE 8—Except for some red formulas, few inks fluoresce in their
dried state on paper. A fluorescent halo is occasionally observed around an
ink line; capillary migration of a vehicle component into the substrate is
a known cause.

7.2.2 Note and record any effect of the substrate. Strong
fluorescence of the paper may affect the observer’s perception
of the ink.
7.2.3 UV examination may reveal indications that the document has been stained by chemicals or other material that may
affect the ink comparison as discussed in Section 5 (7, 8, 9).
These can include the detection of the use of chemical ink
eradicators, liquid or dry opaquing material, cellophane or
other tape, adhesives, etc., that may have significance beyond
the ink comparison. These should be noted and recorded.
7.3 Infrared (IR) Examination:
7.3.1 Determine the Reflected Infrared (RIR) and Infrared
Luminescence (IRL) characteristics of the ink: As these effects
are beyond the range of human vision, some technological
extension of the eye is required.
7.3.1.1 These characteristics may be photographed with IR
sensitive film or observed directly with an IR image conversion
device (7, 8, 11, 15, 16, 19, 20, 21). With either system, a
suitable barrier filter is required in front of the lens to block
visible flux (see 6.6.8 and Note 4). For IRL a suitable excitation
source will also be required (see 6.6.9 and Note 5).
NOTE 9—Both photographic and electronic systems work well; each
has its advantages and drawbacks.
Photography provides a permanent, high resolution record of results
and long exposures can capture faint luminescence. However, exposures
can be long (up to 20 min. for faint luminescence), and considerable
experience is required before dispensing with time consuming bracketing
in a series of exposures using different filters (19, 20). The amount of time
required for processing and printing may also be a problem.
Electronic systems, including units with image conversion tubes and
closed circuit television systems, have the advantage of real time results,
facilitating optimization of filter combinations, focus, exposure, etc. (21).
These systems are well suited to screening batches of documents (such as
passports) for alterations. However, resolution is limited, some faint
luminescence may not be easy to detect, and separate photographic or
electronic imaging equipment is required to record results. Modern
integrating infrared video cameras are able to detect faint IR information
that cannot be seen otherwise.

7.3.2 Reflected Infrared (RIR):
7.3.2.1 Record the characteristics as opaque or transparent,
indicating the degree of opacity. The more opaque the ink (the
more it absorbs), the darker it will appear; the less opaque, the

Copyright by ASTM Int'l (all rights reserved); Tue Nov 22 12:31:55 EST 2011
4
Downloaded/printed by
Amanda M. Aycock (Gibson, Dunn & Crutcher LLP) pursuant to License Agreement. No further reproductions authorized.

E1422 – 05
lighter it will appear, until it seems to be transparent or to drop
out. An arbitrary four point scale of −3 to 0 (opaque to
transparent) may assist in recording these observations.
7.3.3 Infrared Luminescence (IRL):
7.3.3.1 Record the IRL characteristics of the ink relative to
the substrate as darker, similar, or lighter, indicating degree as
appropriate. Ink that luminesces more brightly than the substrate will appear lighter than the substrate; strongly luminescent ink may appear to glow brightly. If ink does not luminesce
or does not luminesce as brightly as the substrate, the ink will
appear darker than the substrate (this is sometimes referred to
as black luminescence or negative luminescence). Ink that
luminesces at an intensity similar to that of the substrate
appears invisible, and is said to drop out. An arbitrary seven
point scale of −3 to 0 to +3 (black to indistinguishable to very
bright) may assist in recording these observations.
NOTE 10—Depending on the characteristics of the substrate and the
combination of source or filters, or both, the appearance of ink samples
with the same formula can vary from nonluminescing to strongly
luminescent. The appearance of ink luminescence can be affected by the
amount of ink and the substrate.

7.3.3.2 A luminescent halo is occasionally observed around
an ink line; capillary migration of a vehicle component into the
substrate is a known cause.
7.3.3.3 Inks that luminesce with similar but not identical
intensity can sometimes be differentiated by placing a nonluminescing or brightly luminescing object behind the substrate
(22).
7.4 When recording UV fluorescence, IR absorption, and
IRL characteristics of an ink sample, it is important to note and
record any influence imparted by the substrate. It is also
important to be aware of factors (such as those discussed in
Section 2) that may affect the results of this portion of the
examination (7, 8, 9).
7.5 The reaction of an ink sample can vary at different
wavelengths. Therefore, in differentiation of ink samples it is
useful to use a range of different light sources, filters, filter
combinations, etc. (16) (see Note 4 and Note 5). In noting and
recording the reaction of the ink sample, also record the source,
filters, etc.
CHEMICAL EXAMINATIONS
7.6 Spot Testing and Solubility Testing:
7.6.1 Spot testing of an ink sample can be done directly on
the substrate. Minimal damage to the document is possible if
the solvents are applied in small amounts to the ink line and the
resulting changes are observed under magnification. Spot
testing of an ink sample can be done on a removed sample, if
performing the test in situ is not indicated. These tests can be
used to differentiate ballpoint and non-ballpoint ink based on
the solvent that solubilizes the vehicle, to determine the proper
extraction solvent for subsequent analysis, or to provide
presumptive information on the colorants used in the ink
formula.
NOTE 11—These tests may consume a great deal of material relative to
the amount of information provided.

7.6.2 Spot tests to determine the solubility or color reaction
of an ink sample to various reagents were once widely used to

differentiate ink formulas and to presumptively identify the
constituents of an ink formula. Information on older ink
formula can be found in Osborn (1) and Mitchell (3). A study
of more modern blue ballpoint inks has been conducted, and an
analytical scheme published (23).
7.6.3 At present spot tests are most often used to differentiate ballpoint and non-ballpoint ink based on the solvent that
solubilizes the vehicle. Ballpoint inks are either oil based or
glycol based. Oil based ballpoint inks were used in the earliest
ballpoint pens. Generally, glycol based ballpoint inks (widely
used since around 1950) are very soluble in pyridine. Inks
formulated for fountain pens, porous point pens, and roller
pens are generally water or alcohol based and compositions
that are readily soluble in ethanol and water (1 + 1) (2).
Indelible markers are solvent based and would generally be
soluble in pyridine. Note and record the results. If TLC is
planned, these results can be used for selecting the appropriate
extracting solvent.
7.6.4 These tests, performed in situ or on a removed sample
with various solvents, can be sufficient to determine that two or
more ink samples are not of the same ink formula. In many
situations, once such a determination is made, further testing
may be unnecessary.
7.7 Chromatography—Thin Layer Chromatography
(TLC)—Many forms of chromatography have been used successfully to differentiate writing inks, including paper chromatography, high pressure liquid chromatography (HPLC), gas
chromatography (GC), and thin layer chromatography (TLC).
Except for substrate specific items, the procedure for paper
chromatography is similar to TLC (2, 5).
7.7.1 TLC Sheet/Plate Activation—Activate a TLC sheet/
plate in a pre-heated oven (approximately 100°C for 10 to 15
minutes) immediately prior to spotting. Allow sheet/plate to
cool.
NOTE 12—Heating the sheet/plate merely drives off plate moisture. If
the sheet/plate were stored under ideal desiccate conditions, activation
would theoretically be unnecessary; however, it would still be advisable to
heat the sheet/plate as a precaution.

7.7.2 Sampling for TLC:
7.7.2.1 Using a blunted or hollow boring hypodermic
needle, or similar device, remove a sufficient number of plugs
(usually 7 to 10 plugs of ink from a line are sufficient). If a
scalpel is used, remove about 1 cm of the line. The number of
plugs (or length of line) required depends on the concentration
and solubility of the ink.
7.7.2.2 Avoid sampling areas on a document that may be
contaminated by writing on the reverse, or by stains or other
contaminants on either side. (See Section 2)
7.7.2.3 Place the plugs of ink in a vial.
7.7.2.4 Place the same number of plugs of paper (or the
same size piece of paper) from a control area of the substrate
in another vial.
7.7.2.5 If the writing is limited, microsampling techniques
using a single plug may be necessary (24).
7.7.3 Extracting the Ink:
7.7.3.1 Add approximately 3 to 5 µL of solvent (pyridine for
ballpoint inks or ethanol and water (1 + 1) for non-ballpoint
inks) to the vials. (Other solvents may be used based on the

Copyright by ASTM Int'l (all rights reserved); Tue Nov 22 12:31:55 EST 2011
5
Downloaded/printed by
Amanda M. Aycock (Gibson, Dunn & Crutcher LLP) pursuant to License Agreement. No further reproductions authorized.

E1422 – 05
ease of extraction. The comparison standard inks must have
been extracted using the same solvent.) The amount may vary
depending on the absorptivity of the substrate and the type and
age of the ink line. Adjust the amount of extracting solvent as
needed. If both ballpoint and non-ballpoint ink from the same
sheet of paper (or other substrate) are being analyzed, two
paper control samples will be necessary since the ink extractions will require two solvents and each solvent may extract
different components from the substrate.
7.7.3.2 Gently agitate the plugs and solvent for approximately 1 min or until sufficient extraction has occurred. Note
and record the color of extract in the vial. The use of standard
color notation may be helpful in recording these observations.
(Test Method D1535, NBS Standard Sample No. 2106, NBS
Special Pub. 440)
7.7.4 Spotting the Ink:
7.7.4.1 Spot the extract on the activated TLC sheet/plate
approximately 15 mm from the designated bottom of the plate.
It is important to maintain uniformity in the intensity and size
of the spot (a spot size of approximately 2 to 3 mm works
well). Spots should be placed no closer than 1 cm from either
the left or right side of the plate and should be adequately
separated so they will not interfere with each other during the
migration of the components of the sample. The boundaries
(left and right) of each area to be spotted may be scribed with
a stylus or pencil. Do not place these boundary marks closer
than 1 to 2 mm from the area of the plate to be spotted. This is
so there will be no interference for the solvent system traveling
up the plate. If a pencil is used, do not spot the extract directly
on the pencil mark or in the same lane since many inks contain
carbon or graphite, as do pencils.
7.7.4.2 Numerous ink samples can be analyzed simultaneously by spotting each ink sample and paper blank on the
same chromatographic sheet/plate with sufficient separation to
avoid interference or cross contamination, or both. These spots
should be equal in intensity and size. This is attainable through
manipulation of the number of ink plugs (or length of ink line)
and the amount of extracting solvent. If the maximum number
of samples are to be compared on a sheet/plate, do not spot the
extract closer than 1 cm from either side of the plate.
Extraction spots placed closer to the edge of a plate can cause
a skewed separation that may affect the comparative value of
the chromatogram.
7.7.4.3 Allow the sheet/plate to air dry to remove any
residual solvent. The amount of time will vary depending on
the laboratory conditions and the solvent(s) utilized. Do not
expose the sheet/plate to extreme heat or light during the
spotting procedure. This has been shown to induce changes in
the resultant chromatograms of some ink formulas (5, 9).
7.7.4.4 If the intensity of the spot is weak, it may be
necessary to respot. This is done by carefully applying additional extract directly over the original spot and air drying
again.
NOTE 13—This technique requires experience. It is important to keep
the spot size consistent when respotting (for example, do not spot a 1 mm
spot over an existing 2 mm spot). Otherwise you may create rings that can
skew the appearance of the resulting separation. Respotting can be
accomplished through the careful adjustment of the amount of extract to
be spotted.

7.7.4.5 Use of a suitable calibration standard is recommended. It should be spotted onto the plate in the same manner.
7.7.5 Developing the TLC Sheet/Plate:
7.7.5.1 Place the sheet/plate in a developing tank previously
equilibrated for approximately 15 min with Solvent System I.
The level of solvent in the tank should be between 5 and 10
mm and should not touch the ink extraction spots when initially
submerged. Let the chromatogram develop until the components exhibit sufficient separation to allow comparison or for
approximately 15 min.
7.7.6 Evaluating:
7.7.6.1 Remove the chromatogram from the developing
tank and immediately evaluate the fluorescent characteristics
using long-wave UV and short-wave UV sources. Note and
record the color, the fluorescent characteristics, the retardation
factor (R value), and the relative concentration of all fluorescent bands present for each ink sample.
7.7.6.2 Follow the same procedure for the corresponding
paper (or other substrate) control (blank), to determine if there
is any contribution from the substrate, for example, from
tinting materials or optical brighteners (5).
7.7.6.3 Allow the sheet/plate to air dry and promptly evaluate it again following the same procedures. Note and record
any change.
NOTE 14—The appearance of certain fluorescent components can
change in the time between these two observations.

7.7.6.4 Under ambient light note and record the color, the Rf
value, and the relative concentration of all bands present for
each ink sample and control.
7.7.6.5 The completed plate should be stored away from
light, heat, and air, since, in their separated form, ink dyes are
very susceptible to fading or change of color. Results may be
preserved by color photography.
7.7.7 Interpretation:
7.7.7.1 Samples of ink with qualitatively different colorant
compositions can be easily distinguished by comparison of the
characteristics observed in 7.7.6.
8. Additional Methods
8.1 If more information is needed to distinguish similar
inks, some of the following techniques may be tried.
8.1.1 Additional Thin Layer Chromatography (TLC) Techniques:
8.1.2 Solvent System II allows development in a solvent
system of a different polarity that may affect a different
separation of the components (2, 4).
8.1.3 It may be advisable to use a different TLC sheet/plate
along with the additional solvent systems. This may give a
different separation and allow another means of comparison (2,
4, 10).
8.1.4 The chromatograms can be evaluated with the aid of
laser or other monochromatic illumination, RIR and IRL, or
other techniques described in 7.1.3.
8.1.5 The chromatograms can be imaged and the densities
evaluated using appropriate instrumentation. This can give an
accurate quantitative comparison of the relative concentrations
of components (5).

Copyright by ASTM Int'l (all rights reserved); Tue Nov 22 12:31:55 EST 2011
6
Downloaded/printed by
Amanda M. Aycock (Gibson, Dunn & Crutcher LLP) pursuant to License Agreement. No further reproductions authorized.

E1422 – 05
8.2 Other Analytical Techniques:
8.2.1 These techniques may provide valuable information
concerning components found in inks, including solvents,
surfactants, humectants, and resins. They may be of use in
certain situations, but are not generally necessary in performing routine ink comparisons.
8.2.1.1 Batch-to batch variation within an ink formula may
be detectable utilizing analytical methods, such as chromatography, electrophoresis, spectrometry, spectrophotometry, or a
combination.
8.2.2 Fourier Transform Infrared Spectroscopy (FTIR) can
be useful when detailed information is necessary about an ink’s
organic composition (4, 25).
8.2.3 Gas Chromatography (GC), Gas Chromatography/
Mass Spectrometry (GC/MS) can provide information on
organic components (4). GC/MS operating in the selected ion
monitoring mode permits reliable detection and identification
of the ink’s primary vehicle solvents (28).
8.2.4 High Pressure Liquid Chromatography (HPLC) has
been used to gather information on batch-to-batch variation or
when detailed information is necessary about an ink’s organic
composition (26).
8.2.5 Microspectrophotometry can be used to obtain the
ink’s spectral transmittance curve or reflectance curve, or both
(17).
8.2.6 Spectrofluorometry has been used when an emission
spectra is desired (27).
8.2.7 X-Ray Fluorescence Spectroscopy (XRF) can provide
detailed information on the inorganic components of an ink (5).
8.2.8 Capillary Electrophoresis has been used to provide
detailed organic comparisons of two or more inks (29).
9. Reporting Conclusions
9.1 Conclusions resulting from the comparison of two ink
samples may be reached once sufficient examinations have
been conducted. In reporting conclusions, the tests performed
shall be listed. The number of necessary tests is dependent on
the inks involved.

9.2 Differentiation:
9.2.1 If significant, reproducible, inexplicable differences
between ink samples are found at any level of the optical or
chemical analyses, it may be concluded that the inks do not
have a common origin.
9.2.2 However, when inks give differing test results, the
possibility of batch-to-batch variation within an ink formula
must be considered: this kind of variation may be detectable
utilizing analytical methods, such as chromatography, electrophoresis, spectrometry, spectrophotometry, or a combination.
The potential influences of interfering factors that can alter the
composition of an ink sample must also be considered (see
Section 5).
9.3 Matches:
9.3.1 When the comparison of two or more ink samples by
optical or chemical analyses, or both reveals no significant,
reproducible, inexplicable differences and there is significant
agreement in all observable aspects of the results, it may be
concluded that the ink samples match at that level of analysis
and that the results of the examination indicate that the ink
samples are of the same formula or of two similar formulas
with the same nonvolatile components (2). The possibility that
other analytical techniques might be able to differentiate the
samples should be considered.
9.3.2 This conclusion does not eliminate the possibility that
the ink samples being compared are from different manufacturing batches or from different writing or marking instruments
(2).
9.3.3 Reports of conclusions should never state that two ink
samples are identical or the same ink. Statements must be
within the limits of 9.3.1.
10. Keywords
10.1 forensic sciences; ink comparison; questioned
documents

REFERENCES
(1) Osborn, A. S. Questioned Documents, 2d ed., Boyd Printing Co.,
Albany, NY, 1929.
(2) Crown, D. A., Brunelle, R. L. and Cantu, A. A. “Parameters of
Ballpoint Ink Examination,” Journal of Forensic Sciences, Vol 21,
1976, pp. 917–922.
(3) Mitchell, C. A. Inks: Their Composition and Manufacture, Including
Methods of Examination and a Full List of British Patents, 4th ed.,
Charles Griffin & Co., Ltd., London, 1937.
(4) Brunelle, R. L. and Pro, M. J. “A Systematic Approach to Ink
Identification,” Journal of Offıcial Analytical Chemistry, Vol 55,
1972, pp. 823–826.
(5) Brunelle, L. R. and Reed, R. W. Forensic Examination of Ink and
Paper, Charles C Thomas, Springfield, IL, 1984.
(6) Kelly, J. D. and Cantu, A. A. “Proposed Standard Methods for Ink
Identifications,” Journal of Offıcial Analytical Chemistry, Vol 58,
1975, pp. 122–125.

(7) Ordidge, M. and Totty, R. N. “The Examination of Ink Writing on
Photographic Paper,” Journal of the Forensic Science Society, Vol 24,
1984, pp. 43–47.
(8) Sensi, C. A. and Cantu, A. A. “Infrared Luminescence: Is It a Valid
Method to Differentiate Among Inks?” Journal of Forensic Sciences,
Vol 27, 1982, pp. 196–199.
(9) Stewart, L. F. “Artificial Aging of Documents,” Journal of Forensic
Sciences, Vol 27, 1982, pp. 450–453.
(10) Hamilton, R. J. and Hamilton, S. Thin Layer Chromatography, John
Wiley & Sons, Inc., Chichester, UK, 1987.
(11) Godown, L. “New Nondestructive Document Testing Methods,”
Journal of Criminal Law, Criminology, and Police Science, Vol 55,
1964, pp. 280–286.
(12) Eastman Kodak, Kodak Filters for Scientific and Technical Uses.
Eastman Kodak Co., Rochester, NY.
(13) Kopp, Color Filter Glasses, Kopp Glass, Pittsburgh, PA, 1986.

Copyright by ASTM Int'l (all rights reserved); Tue Nov 22 12:31:55 EST 2011
7
Downloaded/printed by
Amanda M. Aycock (Gibson, Dunn & Crutcher LLP) pursuant to License Agreement. No further reproductions authorized.

E1422 – 05
(14) Schott, Optical Glass Filters, Schott Glass Technologies, Durea, PA.
(15) Hoover, H. L. and MacDonell, H. L. “Infrared Luminescence Using
Glass Filters,” Journal of Forensic Sciences, Vol 9, 1964, pp. 89–99.
(16) Veillon, P., Rothenbuehler, O. and Mathyer, J. “Some Remarks on the
Optical Examination of Inks,” International Criminal Police Review, Vol 27, No. 11, November 1972. No. 262, pp. 238–255.
(17) Zeichner, A., et al. “Transmission and Reflectance Microspectrophotometry of Inks,” Journal of Forensic Sciences, Vol 33, 1988, pp.
1171–1184.
(18) Eastman Kodak, Ultraviolet and Fluorescence Photography. Eastman Kodak Co., Rochester, NY.
(19) Costain, J. E. and Lewis, G. W. “A Practical Guide to Infrared
Luminescence Applied to Questioned Document Problems,” Journal of Police Science and Administration, Vol 1, 1973, pp. 209–218.
(20) Eastman Kodak, Applied Infrared Photography, Eastman Kodak
Co., Rochester, NY.
(21) Richards, G. B. “The Application of Electronic Video Techniques to
Infrared and Ultraviolet Examinations,” Journal of Forensic Sciences, Vol 23, 1977, pp. 53–60.
(22) Radley, R. W. “Examination of Infrared Luminescence Responses of
Ballpoint Inks Using Luminescent Backgrounds,” International
Journal of Forensic Document Examiners, Vol 2, No. 2, April/June
1996, pp. 151–152.
(23) Crown, D. A., Conway, J. A. and Kirk, P. L. “Differentiation of Blue

Ballpoint Pen Inks,” Journal of Criminal Law, Criminology, and
Police Science, Vol 52, 1961, pp. 338–343.
(24) Kuranz, R. L. “Technique for Transferring Ink from a Written Line to
a Thin-Layer Chromatographic Sheet,” Journal of Forensic Sciences, Vol 31, 1986, pp. 655–657.
(25) Humecki, H. “Experiments in Ballpoint Ink Aging Using Infrared
Spectroscopy,” Proceedings of International Symposium on NonHandwriting Aspects of Questioned Document Examination, U.S.
Government Printing Office, Washington, DC, 1985, pp. 131–135.
(26) Lyter, A. H. “Examination of Ballpen Ink by High Pressure Liquid
Chromatography,” Journal of Forensic Sciences, Vol 27, 1982, pp.
154–160.
(27) Kelly, J. H. “Spectrofluorometric Analyses of Ball Point Ink,”
Journal of Police Science and Administration, Vol 1, 1973, pp.
175–181.
(28) Aginsky, V. N. “Dating and Characterizing Writing, Stamp Pad and
Jet Printer Inks by Gas Chromatography/Mass Spectrometry,” International Journal of Forensic Document Examiners, Vol 2, No. 2,
April/June 1996, pp. 103–115.
(29) Fanali, S. and Schudel, M. “Some Separations of Black and Red
Water-Soluble Fiber-Tip Pen Inks by Capillary Zone Electrophoresis
and Thin Layer Chromatography,” Journal of Forensic Sciences,
Vol 36, 1991, pp. 1192–1197.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or [e-mail] (e-mail); or through the ASTM website
(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/
COPYRIGHT/).

Copyright by ASTM Int'l (all rights reserved); Tue Nov 22 12:31:55 EST 2011
8
Downloaded/printed by
Amanda M. Aycock (Gibson, Dunn & Crutcher LLP) pursuant to License Agreement. No further reproductions authorized.