ASTM D6488-08(2013)
(Terminology)Standard Terminology Relating to Print Problems
Standard Terminology Relating to Print Problems
SIGNIFICANCE AND USE
3.1 A common set of definitions is essential to improve communication and avoid misunderstanding among ink makers, substrate makers, and printers.
3.2 The term “paper” in this standard also encompasses the term “paperboard.”
3.3 Definitions that are verbatim from one of the referenced sources are indicated by giving the acronym of the organization or the author of the book at the end of the definition.
SCOPE
1.1 This terminology standard gives definitions for problems that develop with printed matter as a result of deficiencies in the ink, substrate, press, or combinations thereof.
1.2 These definitions cover the three major printing processes and are given in the following sequence: lithography, flexography, and gravure. For further information see Refs (1-4) at the end of this standard.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6488 − 08 (Reapproved 2013)
Standard Terminology Relating to
Print Problems
This standard is issued under the fixed designation D6488; 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.
DISCUSSION—It results from moisture being trapped under the dried
1. Scope*
ink film during heatset drying. This condition is more common with
1.1 This terminology standard gives definitions for prob-
higher ink coverage and heavier basis weight papers.
lems that develop with printed matter as a result of deficiencies
blocking, n—an undesired adhesion between sheets of printed
in the ink, substrate, press, or combinations thereof.
material that might occur under moderate pressure or in-
1.2 These definitions cover the three major printing pro-
creased temperature, or both, while in storage or in use.
cesses and are given in the following sequence: lithography,
DISCUSSION—Damage to one or both surfaces may be visible upon
flexography, and gravure. For further information see Refs
separation and may be due to improperly dried ink or coating.
(1-4) at the end of this standard.
bronzing, n—the metal-like reflectance which sometimes ap-
2. Referenced Documents pears at the surface of nonmetallic colored materials.
DISCUSSION—Bronzing is perceived at the specular angle by observ-
2.1 ASTM Standards:
ing the image of a white light source, for example, and is characterized
D4361 Test Method for Apparent Tack of Printing Inks and
by a distinct hue of different dominant wavelengths than the hue of the
Vehicles by a Three-Roller Tackmeter
color itself. The origin of the selective specular reflectance observed is
F425 Terminology Relating to Lithographic Copy Products generally considered to be reflectance from very small particle size
pigment partially separated from surrounding vehicle at or near the ink
(Withdrawn 2003)
film surface.
3. Significance and Use
catch up, n—a condition that occurs when the non-image area
3.1 A common set of definitions is essential to improve
of the plate becomes ink receptive. See scum. [GATF]
communication and avoid misunderstanding among ink DISCUSSION—This condition results from the insufficient feeding of
dampening solution.
makers, substrate makers, and printers.
3.2 The term “paper” in this standard also encompasses the chalking, n—see powdering.
term “paperboard.”
coating pick, n—the removal of coating particles from the
3.3 Definitions that are verbatim from one of the referenced
sheetsurfacethatoccurswhenthetackoftheinkexceedsthe
sourcesareindicatedbygivingtheacronymoftheorganization
surface strength of the substrate.
or the author of the book at the end of the definition.
DISCUSSION—A loss in surface strength may occur during printing
when the coating is resolubilized by the fountain solution.
4. Terminology
crocking, n—smudging or rubbing off of ink.
4.1 Definitions:
dot distortion, n—an undesired change in shape of halftone
4.1.1 Lithographic Printing:
dots during plate making or printing operations, or both.
blistering, n—the formation of small air pockets under the
printed paper surface.
dot doubling, n—the unintentional printing of two images
slightly out of register from a single form.
DISCUSSION—Dot doublings can be the result of a mechanical
This terminology is under the jurisdiction of ASTM Committee D01 on Paint
problem due to undesired movement between the plate and the blanket.
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.56 on Printing Inks.
dot gain, n—the increase in halftone dot size in relation to the
CurrenteditionapprovedJune1,2013.PublishedJuly2013.Originallyapproved
dots on the lithographic film; it is the arithmetic difference
in 1999. Last previous edition approved in 2008 as D6488 – 08. DOI: 10.1520/
D6488-08R13.
between the dot area on the original film and dot area on the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
printed sheet.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
DISCUSSION—Physical dot gain can be caused by a number of the
Standards volume information, refer to the standard’s Document Summary page on
processing steps in prepress or during actual printing. Factors that
the ASTM website.
control dot gain on press are ink film thickness, amount of water feed,
The last approved version of this historical standard is referenced on
www.astm.org. solid print density, ink holdout/absorbance characteristics of the paper,
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6488 − 08 (2013)
screen ruling, blanket release, pressure between the blanket and plate, gripper edge in a defective solid because the reverse leaves excess ink
and pressure between the blanket and paper. Optical dot gain results on the form rollers; the ghosts are further away from the gripper edge
from light scattering in the paper.The dot gain value can be determined than the reverse.
using a dosimeter that calculates the apparent dot size on the print as
hickey, n—an imperfection caused by dirt, hardened ink, paper
compared with the original dot size based on the density of the solid.
debris or other unwanted particles that cling to the press or
dot loss, n—the total or partial loss of the smallest dots on the
plate during printing.
sheets, usually in the areas of 25 % screen or less.
DISCUSSION—Hickeys appear as either small solid printed areas
DISCUSSION—Dot loss can be due to plate or blanket buildup caused
surrounded by a white halo or as unprinted spots surrounded by printed
byanundesiredreactionbetweenthepaperandfountainsolution.(Also
ink.
referred to as disappearing dot or vanishing dot.)
hickey, halo, n—a doughnut shaped hickey with an inked
dot slur, n—dot gain that occurs in a pronounced direction and
center, often caused by foreign particles such as ink skin.
is not symmetrical.
[TAPPI]
DISCUSSION—Slur is caused by mechanical problems with the drive
and speed of the plate and blanket cylinders.
hickey, void, n—a totally un-inked spot on the printed sheet,
often caused by dust or pick-outs that adhere to the offset
doubling, n—a printing defect in offset printing products (and
blanket or plate, thereby interfering with transfer of ink.
other indirect printing processes) that manifests itself as a
doubled or multiple (shadow-like) contour of the image
ink fading, n—term used in offset printing for the variation in
elements. [KIPPHAN]
the ink density (uneven ink film) in the direction of print (as
DISCUSSION—Mechanical vibration and register deviations during the
a consequence of inking unit design and content of the
printingprocesscancausedoubling.Doublingcanoccurinsingle-color
printing sheet). [KIPPHAN]
printing but is a special danger in mulitcolor printing. As is the case
with slurring, doubling results in dot grain.
ink over-emulsification, n—a condition that occurs when a
lithographic ink picks up too much dampening solution
embossing, n—the tendency of a paper to take a permanent
resulting in a weak print or snowflake pattern.
pattern, either depressed or raised, as a result of contact with
the blanket during printing. [TAPPI]
ink misting, n—the ejection of fine particles of ink into the air
andontothepress,occurringwhentheinkfilmsplitsinmore
fan-out effect, n—widening of the paper web in a web-fed
than one place.
press, normally caused by dampening but also by printing
DISCUSSION—The centrifugal forces generated by high speed rollers
pressure, which can theoretically occur in sheet-fed printing
can cause this problem. Long inks are more susceptible to misting than
as well. [KIPPHAN]
short inks.
fiber pick, n—the delaminating, splitting, or tearing of paper
ink refusal, n—the failure of a roller or plate to accept ink.
surface fibers that occurs when the force between the paper
Alternative term: stripping—see Gravure Printing.
and blanket exceeds the surface strength of the paper.
DISCUSSION—The condition can be caused by gum buildup on the
roller or plate in the image areas.
flying, n—the tendency of a printing ink or vehicle to be
ejected as large globules from a roller distribution system.
ink setoff, n—the undesirable transfer of an ink in any printing
[D4361]
process from fresh prints to any other surface.
DISCUSSION—See also misting and spraying for comparison.
DISCUSSION—This printing defect is caused by slow setting inks or
insufficient spray powder.
ghosting, chemical, n—the appearance of gloss or dull mirror
images that are printed on the reverse side of the sheet.
marking, n—the removal of printed ink from the web to idler
DISCUSSION—This phenomenon is usually caused by chemical activ-
rolls, turn bars, or nose cone on a printing press.
ity of the ink during the drying phase of oxidative inks.
DISCUSSION—Printing ink may then be redeposited on subsequent
printed sheets.
ghosting, mechanical, n—the appearance of a phantom image
on the printed side of the sheet.
milking, n—a white colored buildup on the non-image areas of
DISCUSSION—These images can be caused by some mechanical factor
the offset blanket that usually occurs when the paper coating
in plate preparation, press settings or mechanical problems.
or paper filler (in the case of uncoated paper) softens due to
ghosting, starvation, n—mechanical ghosting that appears in
inadequate water resistance.
solids and shadows as either a lighter image or a darker
misting, n—side effect of ink film splitting within an inking
image than the background.
unit, in particular on rapidly-rotating inking rollers.
DISCUSSION—Thebasiccauseisalayoutthatistoodemandingforthe
[KIPPHAN]
inking capacity of the particular press.
(a) light print ghosting: a lighter image within the primary image. DISCUSSION—Here, extremely small droplets (diameter of 10 to
Light ghosts are defects in a print solid after other solids (for example, 50µm) of ink are released from the ink layers on the exiting nip. They
large letters) strip too much ink off the form rollers. This occurs when form an aerosol with the ambient air, can lead to printing defects, and
the other solids are next to the gripper edge, between it and the contribute to soiling of the press. Misting is very much dependent on
defective solid. the rheology of the ink, as well as on the velocity of the ink-carrying
(b) dark print ghosting: a darker image within the primary image. surface and the geometry of the rollers. See also spraying and flying for
Dark ghosts result, for example, from reverse block letters near the comparison.
D6488 − 08 (2013)
moiré, n—an undesirable, unintended interference pattern plate tinting, n—the existence of a weak coloration from the
caused by the out-of-register overlap of two or more regular fountain solution onto the non-image area of the plate.
patterns such as dots or lines.
DISCUSSION—The condition occurs when pigments, with or without
ink ingredients, become solubilized or emulsified into the fountain
DISCUSSION—In process color printing, screen angles are selected to
solution.
minimize this pattern. If the angles are not correct, an objectionable
effect may be produced.
plate wear, n—a physical abrading away of the non-image or
mottle, back trap, n—a nonuniform density variation of a
image area, or both, of the plate.
printed ink film due to nonuniform ink absorption into the
DISCUSSION—This erosion can be caused by abrasive materials in the
paper. ink or on the substrate.
DISCUSSION—This results in nonuniform transfer of the ink back onto
powdering, n—a condition where ink easily rubs off a print
the blankets of subsequent printing units of the press, which in turn is
after the normal drying period.
transferred onto the following sheets (or web) of paper.
DISCUSSION—Also referred to as “chalking.” Powdering could be due
mottle, halftone, n—a nonuniform transfer of halftone dots.
to the rapid absorption of the vehicle into the paper or the improper
DISCUSSION—This condition can be caused by factors such as
pigment to binder ratio in the ink.
irregularities in paper surface, variations in ink transfer properties or
emulsified ink.
print void, n—a defective spot of unprinted matter in a print
solid or halftone that can be caused by a buildup of foreign
mottle, print, n—an uneven appearance within the continuous
matter on the plate or blanket.
ink film solid areas of a print, with respect to density, gloss
or color.
railroad tracks, n—a pattern on the printed sheet extending in
DISCUSSION—Also referred to as “solid area mottle.” This effect may
themachinedirectionthatiscomprisedofoneormorelinear
be caused by a varying ink film due to the uneven ink receptivity and
regions. [TAPPI]
absorbency of the paper or by poorly ground ink.
DISCUSSION—This effect may be caused by excessive variations in
drying across the width of the web.
mottle, trapping, n—nonuniform print due to improper tack
sequence of the inks.
scum, n—a condition that occurs when a lithographic plate has
DISCUSSION—If the first down ink is lower in tack on the substrate’s
become sensitized in the non-image areas and these areas
surface, subsequent ink film(s) will not trap uniformly. In this situation,
begin to take ink. [GATF]
it is not uncommon for the first down color to also be pulled off the
printing substrate onto downline units causing poor density and ink
set-off, n—the unintentional transfer of part of an image or ink
color contamination.
from its intended location to another surface. [F425]
mottle, water interference, n—nonuniform print caused by
show-through, n—the printed image can be observed on the
poor ink transfer due to the printing substrates’ inability to
opposite side of the sheet under normal lighting conditions.
absorb fountain solution.
DISCUSSION—This condition can be caused by a heavy ink film, ink
strike-through, or low substrate opacity.
paper linting, n—the picking off of loosely bonded paper
surface fibers, or dust, or both, that can accumulate on an
slinging, n—see spraying.
offset plate or blanket interfering with print quality.
DISCUSSION—This condition is usually associated with uncoated
slip roll ink buildup, n—an undesirable accumulation of ink
paper.
on the dampening rolls of a continuous type dampening
system.
pigment bleed, n—a condition in which some of the ink
pigment is dispersed in the dampening solution and deposits
slurring, n—slurring is a printing defect that occurs in offset
on the non-image area of t
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