ASTM E2494-07
(Guide)Standard Guide for Examination of Typewritten Items
Standard Guide for Examination of Typewritten Items
SCOPE
1.1 This guide covers procedures that should be used by forensic document examiners (Guide E 444) for examinations and comparisons involving typewritten items and related procedures.
1.2 These procedures are applicable whether the examination and comparison is of questioned and known items or of exclusively questioned items.
1.3 These procedures include evaluation of the sufficiency of the material (questioned, or known, or both) available for examination.
1.4 Procedures are also given for taking exemplars from typewriters and the proper handling of typewriters or parts of typewriters that might be relevant.
1.5 These methods can also be applicable (in whole or in part) to examinations of documents prepared on other impact and nonimpact printing devices.
1.6 The particular methods employed in a given case will depend upon the nature of the material available for examination.
1.7 This guide might not cover all aspects of unusual or uncommon examinations of typewritten items.
1.8 This guide cannot replace training (Guide E 2388) or experience and should be used in conjunction with professional judgment.
1.9 The values stated in inch pound units are to be regarded as the standard. The values given in parentheses are for information only.
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.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:E2494–07
Standard Guide for
Examination of Typewritten Items
This standard is issued under the fixed designation E 2494; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope E 444 Descriptions of Scope of Work Relating to Forensic
Document Examiners
1.1 This guide covers procedures that should be used by
E 1658 Terminology for Expressing Conclusions of Foren-
forensic document examiners (Guide E 444) for examinations
sic Document Examiners
and comparisons involving typewritten items and related
E 1732 Terminology Relating to Forensic Science
procedures.
E 2195 Terminology Relating to the Examination of Ques-
1.2 These procedures are applicable whether the examina-
tioned Documents
tion and comparison is of questioned and known items or of
E 2287 Guide for Examination of Fracture Patterns and
exclusively questioned items.
Paper Fiber Impressions on Single-Strike Film Ribbons
1.3 These procedures include evaluation of the sufficiency
and Typed Text
of the material (questioned, or known, or both) available for
E 2388 Guide for Minimum Training Requirements for
examination.
Forensic Document Examiners
1.4 Procedures are also given for taking exemplars from
F 221 Terminology Relating to Carbon Paper and Inked
typewriters and the proper handling of typewriters or parts of
Ribbon Products and Images Made Therefrom
typewriters that might be relevant.
F 909 Terminology Relating to Printers
1.5 These methods can also be applicable (in whole or in
F 1457 Terminology Relating to Laser Printers
part) to examinations of documents prepared on other impact
and nonimpact printing devices.
3. Terminology
1.6 The particular methods employed in a given case will
3.1 For definitions of terms in this Guide, refer to Termi-
depend upon the nature of the material available for examina-
nology E 1732 and Terminology E 2195. Some useful defini-
tion.
tions of terms can also be found in the other Terminology
1.7 This guide might not cover all aspects of unusual or
standards in 2.1.
uncommon examinations of typewritten items.
3.2 Definitions:
1.8 This guide cannot replace training (Guide E 2388)or
3.2.1 ball element, n—an element used in a single element
experienceandshouldbeusedinconjunctionwithprofessional
typewriter in which the fully formed characters are located on
judgment.
the outer surface of a sphere-like device. Frequently called
1.9 The values stated in inch pound units are to be regarded
golf-ball element.
as the standard. The values given in parentheses are for
3.2.2 baseline, n—the ruled or imaginary line upon which
information only.
typewriting appears to rest.
1.10 This standard does not purport to address all of the
3.2.3 carbon paper, n—a sheet composed of a supporting
safety concerns, if any, associated with its use. It is the
substrate on one or both sides of which is a coating containing
responsibility of the user of this standard to establish appro-
atransferable(usuallycolored)material.Thecoatingisofsuch
priate safety and health practices and determine the applica-
nature that it will transfer in part or entirely to a copy sheet at
bility of regulatory limitations prior to use.
the point of pressure contact. F 221
2. Referenced Documents 3.2.4 character, n—any language symbol (for example,
letter, numeral, punctuation mark, or other sign), other symbol,
2.1 ASTM Standards:
or ornament. E 2195
3.2.5 character pitch, n—the number of characters that can
This guide is under the jurisdiction of ASTM Committee E30 on Forensic
be printed in a horizontal 1 in. (25.4 mm). F 1457
Sciences and is the direct responsibility of Subcommittee E30.02 on Questioned
3.2.6 character spacing, n—the width allotted to each
Documents.
character in a fixed pitch (monospacing) typewriter or to the
Current edition approved April 1, 2007. Published June 2007.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
basic unit in a proportional spacing typewriter; usually ex-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
pressed in millimeters or as a fraction of an inch. Synonym for
Standards volume information, refer to the standard’s Document Summary page on
horizontal escapement.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E2494–07
3.2.7 correctable ribbon, n—a ribbon that produces an still result in full characters being printed. F 221
image that is designed to be completely removed from the
3.2.24 nonimpact printer, n—a printer in which image
substrate by means of lift-off.
formation is not the result of mechanical impacts. F 909
3.2.8 correction media, n—ribbons, tapes, and sheets de-
3.2.25 original typed text, n—typed text imprinted onto the
signed to be struck by the typeface to cover-up or lift-off typed
surface of a substrate as the result of the impact of a typeface.
text.
3.2.26 printer, n—an output unit that produces durable
3.2.9 cover-up, n—the obliteration of one or more images
hard-copy record of data in the form of a sequence of discrete
by means of an opaque material similar in color to the
graphic characters belonging to a predetermined character set.
substrate. F 221
F 909
3.2.10 daisy wheel element (print wheel), n—an element
3.2.27 proportional spacing, n—a system of printing where
used in a typewriter in which the fully formed characters are
the character spacing is set in accordance with the character
contained on the ends of finger-like projections radiating out
width. See fixed pitch.
from the center of a disk.
3.2.28 single element typewriter, n—a typewriter that gen-
3.2.11 electric typewriter, n—a typewriter in which an
erates text via interchangeable “elements” that each contain a
electromechanical device causes the type element to be acti-
full set of characters.
vated when the keys are struck. F 909
3.2.29 single-strike film ribbon, n—aninkedribbonwherein
3.2.12 electronic typewriter, n—an electric typewriter in
the substrate is a plastic film material such as polyethylene,
whichthekeyboardinputisreceivedbyanelectronicprocessor
where each area of the ribbon is capable of producing only one
built into the typewriter. This unit then controls the print head
image. F 221
and other features to produce the typing action. F 909
3.2.30 single-strike paper ribbon, n—an inked ribbon
3.2.13 element, n—the interchangeable typeface carrier of a
wherein the substrate is paper, where each area of the ribbon is
single element typewriter. See ball element, daisy wheel
capable of producing only one image. F 221
element, thimble element.
3.2.31 thimble element, n—an element used in a typewriter
3.2.14 fabric ribbon, n—an inked ribbon wherein the sub-
in which the fully formed characters are located on the ends of
strate is a woven cloth material, such as nylon, cotton, silk, etc.
finger-like devices that are similar to a daisy wheel except that
F 221
the device is formed to produce a cup-like or thimble structure.
3.2.15 fixed pitch, adj—describes a character set in which
3.2.32 thread count, n—the total number of warp and filling
all character cells are of equal width. (See proportional
threads in one square inch of fabric. F 221
spacing.) F 1457
3.2.16 impact printer, n—a printer in which printing is the 3.2.33 typebar, n—a bar, mounted on a typewriter, that
holds a type slug(s).
result of mechanical impacts.
3.2.17 individualizing characteristics, n—marks or proper- 3.2.34 type element, n—see element.
ties that serve to uniquely characterize.
3.2.35 typeface, n—the portion of the element or type slug
3.2.17.1 Discussion—Both class characteristics (marks or
that projects from the body and contacts the surface of the
properties that associate individuals as members of a group)
substrate to form the character.
and individual characteristics (marks or properties that differ-
3.2.36 type slug, n—the block (usually metal) attached to
entiate the individual members in a group) are individualizing
the end of the typebar that bears the typeface.
characteristics.
3.2.37 typestyle, n—a particular variant of a type design.
3.2.18 inked ribbon, n—a ribbon composed of a supporting
3.2.38 typestyle classification scheme, n—a hierarchical
substrateoffilm,fabric,orpaperandacoatingorimpregnation
taxonomic schematic, key, or computer database that can be
of a coloring material. The coloring material is of such nature
used to determine the source of a particular typestyle.
thatitwilltransferinpartorentirelytoacopysheetatthepoint
3.2.38.1 Discussion—These schemes are only an aid for
of pressure contact. F 221
searching a typestyle library and are not a substitute for actual
3.2.19 lift-off, n—the removal of one or more images of
reference materials in the typestyle library.
copy from the substrate by transferring to an intermediate
3.2.39 typestyle library, n—an organized collection of ref-
member. F 221
erence samples of typestyles and related materials.
3.2.20 line spacing, n—the distance between successive
3.2.39.1 Discussion—Reference materials can also include
lines of text, usually measured from baseline to baseline, and
information such as typestyle catalogs, treatises relative to
usually expressed in millimeters or as lines per inch for
typography and the design of typestyles used on typewriters
typewritten text. Synonym for vertical escapement.
and other printing systems, typewriters, type slugs, type
3.2.21 manual typewriter, n—a typewriter whose operation
elements, actual strike-ups, and instruction and repair manuals.
depends solely upon the mechanical action powered by the
Available relevant data on each typestyle should be collected
operator.
and maintained.
3.2.22 monospacing, n—see fixed pitch.
3.2.40 typewriter, n—a self-contained machine for
3.2.23 multi-strike film ribbon, n—a ribbon wherein the
character-by-character direct writing by means of keyboard-
substrate film such as polyester is coated or impregnated with
operated typefaces.
an ink which allows several different imprints to be made from
multiple overstrikes on the same location on the ribbon, and 3.3 Definitions of Terms Specific to This Standard:
E2494–07
3.4 alignment, n—the adjustment of various mechanisms of procedures, a forensic document examiner can reliably reach
a typewriter to ensure the even printing of the characters and an opinion concerning the source of the item(s) examined.
their proper positioning relative to the baseline and to the other 4.2 The examinations described in this guide pertain to
characters. those documents prepared on typewriters and can consist of a
wide range of forensic examinations. Some or all of these
3.5 alignment defect, n—a deviation from the intended
appearance or position of a character relative to another procedures can also be applicable to examinations of docu-
ments prepared on other impact and nonimpact printing de-
character. see impression defect, motion defect.
3.5.1 Discussion—Alignment defects are usually catego- vices.
4.2.1 Examinations can be conducted to classify a typestyle
rized as vertical misalignment (character too high or low
relative to the baseline established by the other characters), and to determine the possible make and model of typewriter(s)
by comparison with a typestyle library.
horizontal misalignment (character too far to the left or right
relative to other characters), and twisted or leaning (character 4.2.2 Examinations and comparisons of typewritten docu-
ments can be conducted for the purpose of determining
leans to the left or to the right); because they are corrected in
the alignment process, impression defects are considered as whether or not they are from a common source.
4.2.3 Examinations and comparisons of typewritten docu-
alignment defects.
ments may be conducted for the purpose of determining
3.6 bead defect, n—inked or uninked impression or hole in
whether or not they were produced using a particular type-
the paper caused by a contaminant particle encased in plating
writer or type element.
material located on or adjacent to the printing area of the
4.2.4 Examinations and comparisons of a typewritten docu-
typeface on a metal coated element.
ment(s) with a typewriter (or particular part(s) of a typewriter)
3.7 family (of type), n—a class of type designs sharing basic
or type element can be conducted for the purpose of determin-
qualities of style and artistic expression that differentiate it
ing whether or not a document was prepared with that
from other similar designs.
equipment.
3.8 flashing, n—excess material from the molding process.
4.2.5 Examinations and comparisons of a typewritten docu-
3.9 impression defect, n—a deviation from the intended
ment(s) with typewritten documents of known date can be
evenness in appearance of a character over the entire impres-
conducted for the purpose of determining whether or not a
sion of the character or relative to the impression of another
document was prepared on or about the date indicated.
character. (see off-foot.)
4.2.6 Examinations of typewritten documents can be con-
3.10 motion (as related to typebar typewriters), n—the
ducted for the purpose of determining whether or not a
distance traveled by the mechanism for case shifting (usually
document was typed in a single, continuous operation.
by the typebar segment or the carriage) and the corresponding
4.2.7 Examinations of typewriter ribbons or correction me-
separation of the characters on the type slug.
dia (see lift-off and cover-up), or both, can be conducted to
3.11 motion defect (as related to typebar typewriters), n—a
determine the content or source of the material typed on them
deviation from the intended evenness in appearance of the
or corrected with them, respectively.
baseline alignment of unshifted characters relative to shifted
characters.
5. Interferences
3.12 off-foot, n—the lack of desired and optimum unifor-
5.1 Items submitted for examination can have inherent
mity of contact between the typeface and the substrate.
limitations that can interfere with the procedures in this guide.
3.12.1 Discussion—While the on-feet adjustment of the
Limitations should be noted and recorded.
typewriter evens the impression of the upper and lower
5.2 Limitations can be due to submission of nonoriginal
portions of all the characters, this term is also applied to
documents, or condition of the items submitted for examina-
uneven impressions that are heavier or lighter on the sides or
tion. Other limitations can come fr
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