ASTM D6488-99
(Terminology)Standard Terminology Relating to Print Problems
Standard Terminology Relating to Print Problems
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 The 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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D 6488 – 99
Standard Terminology Relating to
Print Problems
This standard is issued under the fixed designation D 6488; 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 coating pick, n—the removal of coating particles from the
sheet surface that occurs when the tack of the ink exceeds the
1.1 This terminology standard gives definitions for prob-
surface strength of the substrate.
lems that develop with printed matter as a result of deficiencies
in the ink, substrate, press, or combinations thereof.
DISCUSSION—A loss in surface strength may occur during printing
1.2 The definitions cover the three major printing processes when the coating is resolubilized by the fountain solution.
and are given in the following sequence: lithography, flexog-
dot distortion, n—an undesired change in shape of halftone
raphy, and gravure. For further information see Refs (1-4)at
dots during plate making or printing operations, or both.
the end of this standard.
dot doubling, n—the unintentional printing of two images
slightly out of register from a single form.
2. Significance and Use
2.1 A common set of definitions is essential to improve DISCUSSION—Dot doublings can be the result of a mechanical
problem due to undesired movement between the plate and the blanket.
communication and avoid misunderstanding among ink mak-
ers, paper makers, and printers.
dot gain, n—the increase in halftone dot size in relation to the
2.2 The term “paper” in this standard also encompasses the
dots on the lithographic film; it is the arithmetic difference
term “paperboard”.
between the dot area on the original film and dot area on the
2.3 Definitions that are verbatim from one of the referenced
printed sheet.
sources are indicated by giving the acronym of the organization
DISCUSSION—Physical dot gain can be caused by a number of the
at the end of the definition.
processing steps in prepress or during actual printing. Factors that
control dot gain on press are ink film thickness, amount of water feed,
3. Terminology
solid print density, ink holdout/absorbence characteristics of the paper,
3.1 Definitions:
screen ruling, blanket release, pressure between the blanket and plate,
3.1.1 Lithographic Printing:
and pressure between the blanket and paper. Optical dot gain results
from light scattering in the paper. The dot gain value can be determined
blistering, n—the formation of small air pockets under the
using a dosimeter that calculates the apparent dot size on the print as
printed paper surface.
compared with the original dot size based on the density of the solid.
DISCUSSION—It results from moisture being trapped under the dried
dot loss, n—the total or partial loss of the smallest dots on the
ink film during heatset drying. This condition is more common with
sheets, usually in the areas of 25 % screen or less.
higher ink coverage and heavier basis weight papers.
DISCUSSION—Dot loss can be due to plate or blanket buildup caused
blocking, adv—an undesired adhesion between sheets of
by an undesired reaction between the paper and fountain solution. (Also
printed material that might occur under moderate pressure or
referred to as disappearing dot or vanishing dot.)
increased temperature, or both, while in storage or in use.
dot slur, n—dot gain that occurs in a pronounced direction and
DISCUSSION—Damage to one or both surfaces may be visible upon
is not symmetrical.
separation and may be due to improperly dried ink or coating.
DISCUSSION—Slur is caused by mechanical problems with the drive
catch up, n—a condition that occurs when the non-image area
and speed of the plate and blanket cylinders.
of the plate becomes ink receptive. See scum. [GATF].
embossing, n—the tendency of a paper to take a permanent
DISCUSSION—This condition results from the insufficient feeding of
pattern, either depressed or raised, as a result of contact with
dampening solution.
the blanket during printing. [TAPPI]
fiber pick, n—the delaminating, splitting, or tearing of paper
surface fibers that occurs when the force between the paper
These test methods are under the jurisdiction of ASTM Committee D-1 on Paint
and blanket exceeds the surface strength of the paper.
and Related Coatings, Materials, and Applications, and is the direct responsibility of
ghosting, chemical, n—the appearance of gloss or dull mirror
Subcommittee D01.56 on Printing Inks.
Current edition approved Dec. 10, 1999. Published February 2000. images that are printed on the reverse side of the sheet.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 6488
DISCUSSION—This phenomenon is usually caused by chemical activ-
milking, n—a white colored buildup on the non-image areas of
ity of the ink during the drying phase of oxidative inks.
the offset blanket that usually occurs when the paper coating
or paper filler (in the case of uncoated paper) softens due to
ghosting, mechanical, n—the appearance of a phantom image
inadequate water resistance.
on the printed side of the sheet.
moiré, n—an undesirable, unintended interference pattern
DISCUSSION—These images can be caused by some mechanical factor
caused by the out-of-register overlap of two or more regular
in plate preparation, press settings or mechanical problems.
patterns such as dots or lines.
ghosting, starvation, n—mechanical ghosting that appears in
DISCUSSION—In process color printing, screen angles are selected to
solids and shadows as either a lighter image or a darker
minimize this pattern. If the angles are not correct, an objectionable
image than the background.
effect may be produced.
DISCUSSION—The basic cause is a layout that is too demanding for the
mottle, back trap, n—a nonuniform density variation of a
inking capacity of the particular press.
printed ink film due to nonuniform ink absorption into the
(a) light print ghosting: a lighter image within the primary image.
paper.
Light ghosts are defects in a print solid after other solids (for example,
large letters) strip too much ink off the form rollers. This occurs when
DISCUSSION—This results in nonuniform transfer of the ink back onto
the other solids are next to the gripper edge, between it and the
the blankets of subsequent printing units of the press, which in turn is
defective solid.
transferred onto the following sheets (or web) of paper.
(b) dark print ghosting: a darker image within the primary image.
mottle, halftone, n—a nonuniform transfer of halftone dots.
Dark ghosts result, for example, from reverse block letters near the
gripper edge in a defective solid because the reverse leaves excess ink
DISCUSSION—This condition can be caused by factors such as
on the form rollers; the ghosts are further away from the gripper edge
irregularities in paper surface, variations in ink transfer properties or
than the reverse.
emulsified ink.
hickey, n—an imperfection caused by dirt, hardened ink, paper
mottle, print, n—an uneven appearance within the continuous
debris or other unwanted particles that cling to the press or
ink film solid areas of a print, with respect to density, gloss
plate during printing.
or color. Also referred to as “solid area mottle”.
DISCUSSION—Hickeys appear as either small solid printed areas
DISCUSSION—This effect may be caused by a varying ink film due to
surrounded by a white halo or as unprinted spots surrounded by printed
the uneven ink receptivity and absorbency of the paper or by poorly
ink.
ground ink.
hickey, halo, n—a doughnut shaped hickey with an inked
mottle, trapping, n—nonuniform print due to improper tack
center, often caused by foreign particles such as ink skin.
sequence of the inks.
[TAPPI]
DISCUSSION—If the first down ink is lower in tack on the substrate’s
hickey, void, n—a totally un-inked spot on the printed sheet,
surface, subsequent ink film(s) will not trap uniformly. In this situation,
often caused by dust or pick-outs that adhere to the offset
it is not uncommon for the first down color to also be pulled off the
blanket or plate, thereby interfering with transfer of ink.
printing substrate onto downline units causing poor density and ink
ink over-emulsification, n—a condition that occurs when a
color contamination.
lithographic ink picks up too much dampening solution
mottle, water interference, n—nonuniform print caused by
resulting in a weak print or snowflake pattern.
poor ink transfer due to the printing substrates’ inability to
ink misting, n—the ejection of fine particles of ink into the air
absorb fountain solution.
and onto the press, occurring when the ink film splits in more
paper linting, n—the picking off of loosely bonded paper
than one place. The centrifugal forces generated by high
surface fibers, or dust, or both, that can accumulate on an
speed rollers can cause this problem.
offset plate or blanket interfering with print quality.
DISCUSSION—Long inks are more susceptible to misting than short
DISCUSSION—This condition is usually associated with uncoated
inks.
paper.
ink refusal, n—the failure of a roller or plate to accept ink.
piling, n—a buildup of paper, ink or coating on the offset
Alternative term: stripping—see Gravure Printing.
blanket, plate or rollers in such a quantity that it interferes
DISCUSSION—The condition can be caused by gum buildup on the
with print quality. [GATF]
roller or plate in the image areas.
plate binding, n—the refusal of part of a lithographic plate to
ink setoff, n—the undesirable transfer of an ink in any printing produce an image due to loss of ink receptivity.
process from fresh prints to any other surface.
DISCUSSION—This condition is caused by excess hydrophilic material
such as gum.
DISCUSSION—This printing defect is caused by slow setting inks or
insufficient spray powder.
plate wear blinding, n—the failure of the litho plate to print
marking, n—the removal of printed ink from the web to idler
due to erosion in the image area.
rolls, turn bars, or nose cone on a printing press. plate scumming, n—the deposit of ink on the non-image area
of the plate that can be in the form of minute particles or
DISCUSSION—Printing ink may then be redeposited on subsequent
larger continuous solids.
printed sheets.
D 6488
plate tinting, n—the existence of a weak coloration from the bleed, n—the spreading or running of a dye or pigment color
fountain solution onto the nonimage area of the plate. by the action of a solvent.
blocking, n—(see 3.1.1)
DISCUSSION—The condition occurs when pigments, with or without
blooming/blushing, n—a foggy appearance in a printed ink
ink ingredients, become solubilized or emulsified into the fountain
film commonly caused by incompatibility of the ingredients
solution.
in the ink.
plate wear, n—a physical abrading away of the non-image or
caking, n—a settling out of pigments in a fluid ink during
image area, or both, of the plate.
storage (sedimentation).
dry in, n—a situation where the cells in the anilox cylinder
DISCUSSION—This erosion can be caused by abrasive materials in the
ink or on the substrate.
become partly or completely filled with dry ink.
powdering, n—a condition where ink easily rubs off a print DISCUSSION—This reduces print density and may cause loss of detail,
particularly on fine type and highlight dots.
after the normal drying period. Also referred to as“ chalk-
ing”.
feathering, n—a ragged edge on printed type.
DISCUSSION—Powdering could be due to the rapid absorption of the
DISCUSSION—This effect may be caused by poor ink distribution, a
vehicle into the paper or the improper pigment to binder ratio in the ink.
bad impression, excessive ink, or an ink not suitable for the paper.
print void, n—a defective spot of unprinted matter in a print
fill in, n—a condition where the halftone dots and fine type
solid or halftone that can be caused by a buildup of foreign
lose definition because the non-image areas of the plate
matter on the plate or blanket.
between the dots or characters become plugged with dry ink
railroad tracks, n—a pattern on the printed sheet extending in
or a mixture of dry ink and paper fibers.
the machine direction that is comprised of one or more linear
haloing, n—the peripheral lines around print detail caused by
regions. [TAPPI]
excessive ink, excessive roller impression or faulty plate
DISCUSSION—This effect may be caused by excessive variations in
shoulders.
drying across the width of the web.
hickey, n—(see 3.1.1).
ink kick-out, n—the settling of pigment or resin in the bulk
scum, n—a condition that occurs when a lithographic plate has
ink.
become sensitized in the nonimage areas and these areas
ink mottle, n—a condition in which large solid images show
begin to take ink. [GATF]
very localized variations in color strength or gloss, or both.
show-through, n—the printed image can be observed on the
opposite side of the sheet under normal lighting conditions.
DISCUSSION—This condition is caused by an uneven transfer of the
ink from the plate to the substrate, or by nonuniform absorption into the
DISCUSSION—This condition can be caused by a heavy ink film, ink
substrate.
strike-through, or low substrate opacity.
ink sedimentation, n—the settling out of undissolved resin or
slip roll ink buildup, n—an undesirable accumulation of ink
improperly ground pigments.
on the dampening rolls of a continuous type dampening
ink setoff, n—the transfer of ink to the back side of the sheet
system.
or area of the web that is the result of slow drying.
snow flaking, n—the appearance of tiny, white unprinted
moiré, n—(see 3.1.1).
specks (voids) in type or solids, or both, in offset printing
pick off, n—the undesirable removal of a previously printed
that can be caused by excessive emulsification.
ink film in subsequent units of the press due to insufficient
strike-through, n—the penetration of the vehicle of a printing
drying of the ink.
ink through the sheet, so that the ink is apparent on the
piling, n—a build up of paper or ink on the plate.
reverse side under normal lighting conditions.
pinholing, n—the appearance of fine voids in the print area
DISCUSSION—This condition can be caused by heavy ink film,
caused by nonuniform wetting of the substrate or some other
improper ink formulation, or poor ink holdout of the paper.
mechanical problem.
plate swelling, n—an enlargement of rubber or polymer plates
tinting, n—a background wash of color seen uniformly across
due to contact with an incompatible ink, coating, or wash up
the non-image area of a print. See plate tinting.
solvent.
DISCUS
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.