1、Designation: D 6488 08Standard Terminology Relating toPrint Problems1This standard is issued under the fixed designation D 6488; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses ind
2、icates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This terminology standard gives definitions for prob-lems that develop with printed matter as a result of deficienciesin the ink, substrate, press, or combinat
3、ions thereof.1.2 These definitions cover the three major printing pro-cesses and are given in the following sequence: lithography,flexography, and gravure. For further information see Refs(1-4) at the end of this standard.2. Referenced Documents2.1 ASTM Standards:2D 4361 Test Method for Apparent Tac
4、k of Printing Inks andVehicles by a Three-Roller TackmeterF 425 Terminology Relating to Lithographic Copy Prod-ucts33. Significance and Use3.1 A common set of definitions is essential to improvecommunication and avoid misunderstanding among ink mak-ers, substrate makers, and printers.3.2 The term “p
5、aper” in this standard also encompasses theterm “paperboard.”3.3 Definitions that are verbatim from one of the referencedsources are indicated by giving the acronym of the organizationor the author of the book at the end of the definition.4. Terminology4.1 Definitions:4.1.1 Lithographic Printing:bli
6、stering, nthe formation of small air pockets under theprinted paper surface.DISCUSSIONIt results from moisture being trapped under the driedink film during heatset drying. This condition is more common withhigher ink coverage and heavier basis weight papers.blocking, nan undesired adhesion between s
7、heets of printedmaterial that might occur under moderate pressure or in-creased temperature, or both, while in storage or in use.DISCUSSIONDamage to one or both surfaces may be visible uponseparation and may be due to improperly dried ink or coating.bronzing, nthe metal-like reflectance which someti
8、mesappears at the surface of nonmetallic colored materials.DISCUSSIONBronzing is perceived at the specular angle by observ-ing the image of a white light source, for example, and is characterizedby a distinct hue of different dominant wavelengths than the hue of thecolor itself. The origin of the se
9、lective specular reflectance observed isgenerally considered to be reflectance from very small particle sizepigment partially separated from surrounding vehicle at or near the inkfilm surface.catch up, na condition that occurs when the non-image areaof the plate becomes ink receptive. See scum. GATF
10、DISCUSSIONThis condition results from the insufficient feeding ofdampening solution.chalking, nsee powdering.coating pick, nthe removal of coating particles from thesheet surface that occurs when the tack of the ink exceeds thesurface strength of the substrate.DISCUSSIONA loss in surface strength ma
11、y occur during printingwhen the coating is resolubilized by the fountain solution.crocking, nsmudging or rubbing off of ink.dot distortion, nan undesired change in shape of halftonedots during plate making or printing operations, or both.dot doubling, nthe unintentional printing of two imagesslightl
12、y out of register from a single form.DISCUSSIONDot doublings can be the result of a mechanicalproblem due to undesired movement between the plate and the blanket.dot gain, nthe increase in halftone dot size in relation to thedots on the lithographic film; it is the arithmetic differencebetween the d
13、ot area on the original film and dot area on theprinted sheet.DISCUSSIONPhysical dot gain can be caused by a number of theprocessing steps in prepress or during actual printing. Factors that1This terminology is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and
14、 Applications and is the direct responsibility ofSubcommittee D01.56 on Printing Inks.Current edition approved July 1, 2008. Published July 2008. Originally approvedin 1999. Last previous edition approved in 2005 as D 6488 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orco
15、ntact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO B
16、ox C700, West Conshohocken, PA 19428-2959, United States.control dot gain on press are ink film thickness, amount of water feed,solid print density, ink holdout/absorbance characteristics of the paper,screen ruling, blanket release, pressure between the blanket and plate,and pressure between the bla
17、nket and paper. Optical dot gain resultsfrom light scattering in the paper. The dot gain value can be determinedusing a dosimeter that calculates the apparent dot size on the print ascompared with the original dot size based on the density of the solid.dot loss, nthe total or partial loss of the sma
18、llest dots on thesheets, usually in the areas of 25 % screen or less.DISCUSSIONDot loss can be due to plate or blanket buildup causedby an undesired reaction between the paper and fountain solution. (Alsoreferred to as disappearing dot or vanishing dot.)dot slur, ndot gain that occurs in a pronounce
19、d direction andis not symmetrical.DISCUSSIONSlur is caused by mechanical problems with the driveand speed of the plate and blanket cylinders.doubling, na printing defect in offset printing products (andother indirect printing processes) that manifests itself as adoubled or multiple (shadow-like) con
20、tour of the imageelements. KIPPHANDISCUSSIONMechanical vibration and register deviations during theprinting process can cause doubling. Doubling can occur in single-colorprinting but is a special danger in mulitcolor printing. As is the casewith slurring, doubling results in dot grain.embossing, nth
21、e tendency of a paper to take a permanentpattern, either depressed or raised, as a result of contact withthe blanket during printing. TAPPIfan-out effect, nwidening of the paper web in a web-fedpress, normally caused by dampening but also by printingpressure, which can theoretically occur in sheet-f
22、ed printingas well. KIPPHANfiber pick, nthe delaminating, splitting, or tearing of papersurface fibers that occurs when the force between the paperand blanket exceeds the surface strength of the paper.flying, nthe tendency of a printing ink or vehicle to beejected as large globules from a roller dis
23、tribution system.D 4361DISCUSSIONSee also misting and spraying for comparison.ghosting, chemical, nthe appearance of gloss or dull mirrorimages that are printed on the reverse side of the sheet.DISCUSSIONThis phenomenon is usually caused by chemical activ-ity of the ink during the drying phase of ox
24、idative inks.ghosting, mechanical, nthe appearance of a phantom imageon the printed side of the sheet.DISCUSSIONThese images can be caused by some mechanical factorin plate preparation, press settings or mechanical problems.ghosting, starvation, nmechanical ghosting that appears insolids and shadows
25、 as either a lighter image or a darkerimage than the background.DISCUSSIONThe basic cause is a layout that is too demanding for theinking capacity of the particular press.(a) light print ghosting: a lighter image within the primary image.Light ghosts are defects in a print solid after other solids (
26、for example,large letters) strip too much ink off the form rollers. This occurs whenthe other solids are next to the gripper edge, between it and thedefective solid.(b) dark print ghosting: a darker image within the primary image.Dark ghosts result, for example, from reverse block letters near thegr
27、ipper edge in a defective solid because the reverse leaves excess inkon the form rollers; the ghosts are further away from the gripper edgethan the reverse.hickey, nan imperfection caused by dirt, hardened ink, paperdebris or other unwanted particles that cling to the press orplate during printing.D
28、ISCUSSIONHickeys appear as either small solid printed areassurrounded by a white halo or as unprinted spots surrounded by printedink.hickey, halo, na doughnut shaped hickey with an inkedcenter, often caused by foreign particles such as ink skin.TAPPIhickey, void, na totally un-inked spot on the prin
29、ted sheet,often caused by dust or pick-outs that adhere to the offsetblanket or plate, thereby interfering with transfer of ink.ink fading, nterm used in offset printing for the variation inthe ink density (uneven ink film) in the direction of print (asa consequence of inking unit design and content
30、 of theprinting sheet). KIPPHANink over-emulsification, na condition that occurs when alithographic ink picks up too much dampening solutionresulting in a weak print or snowflake pattern.ink misting, nthe ejection of fine particles of ink into the airand onto the press, occurring when the ink film s
31、plits in morethan one place.DISCUSSIONThe centrifugal forces generated by high speed rollerscan cause this problem. Long inks are more susceptible to misting thanshort inks.ink refusal, nthe failure of a roller or plate to accept ink.Alternative term: strippingsee Gravure Printing.DISCUSSIONThe cond
32、ition can be caused by gum buildup on theroller or plate in the image areas.ink setoff, nthe undesirable transfer of an ink in any printingprocess from fresh prints to any other surface.DISCUSSIONThis printing defect is caused by slow setting inks orinsufficient spray powder.marking, nthe removal of
33、 printed ink from the web to idlerrolls, turn bars, or nose cone on a printing press.DISCUSSIONPrinting ink may then be redeposited on subsequentprinted sheets.milking, na white colored buildup on the non-image areas ofthe offset blanket that usually occurs when the paper coatingor paper filler (in
34、the case of uncoated paper) softens due toinadequate water resistance.D6488082misting, nside effect of ink film splitting within an inkingunit, in particular on rapidly-rotating inking rollers. KIP-PHANDISCUSSIONHere, extremely small droplets (diameter of 10 to50m) of ink are released from the ink l
35、ayers on the exiting nip. Theyform an aerosol with the ambient air, can lead to printing defects, andcontribute to soiling of the press. Misting is very much dependent onthe rheology of the ink, as well as on the velocity of the ink-carryingsurface and the geometry of the rollers. See also spraying
36、and flying forcomparison.moir, nan undesirable, unintended interference patterncaused by the out-of-register overlap of two or more regularpatterns such as dots or lines.DISCUSSIONIn process color printing, screen angles are selected tominimize this pattern. If the angles are not correct, an objecti
37、onableeffect may be produced.mottle, back trap, na nonuniform density variation of aprinted ink film due to nonuniform ink absorption into thepaper.DISCUSSIONThis results in nonuniform transfer of the ink back ontothe blankets of subsequent printing units of the press, which in turn istransferred on
38、to the following sheets (or web) of paper.mottle, halftone, na nonuniform transfer of halftone dots.DISCUSSIONThis condition can be caused by factors such asirregularities in paper surface, variations in ink transfer properties oremulsified ink.mottle, print, nan uneven appearance within the continu
39、ousink film solid areas of a print, with respect to density, glossor color.DISCUSSIONAlso referred to as “solid area mottle.” This effect maybe caused by a varying ink film due to the uneven ink receptivity andabsorbency of the paper or by poorly ground ink.mottle, trapping, nnonuniform print due to
40、 improper tacksequence of the inks.DISCUSSIONIf the first down ink is lower in tack on the substratessurface, subsequent ink film(s) will not trap uniformly. In this situation,it is not uncommon for the first down color to also be pulled off theprinting substrate onto downline units causing poor den
41、sity and inkcolor contamination.mottle, water interference, nnonuniform print caused bypoor ink transfer due to the printing substrates inability toabsorb fountain solution.paper linting, nthe picking off of loosely bonded papersurface fibers, or dust, or both, that can accumulate on anoffset plate
42、or blanket interfering with print quality.DISCUSSIONThis condition is usually associated with uncoatedpaper.pigment bleed, na condition in which some of the inkpigment is dispersed in the dampening solution and depositson the non-image area of the plate and then prints as a lightbackground tint. F 4
43、25DISCUSSIONAlso referred to as tinting.piling, na buildup of paper, ink or coating on the offsetblanket, plate or rollers in such a quantity that it interfereswith print quality. GATFplate binding, nthe refusal of part of a lithographic plate toproduce an image due to loss of ink receptivity.DISCUS
44、SIONThis condition is caused by excess hydrophilic materialsuch as gum.plate wear blinding, nthe failure of the litho plate to printdue to erosion in the image area.plate scumming, nthe deposit of ink on the non-image areaof the plate that can be in the form of minute particles orlarger continuous s
45、olids.plate tinting, nthe existence of a weak coloration from thefountain solution onto the non-image area of the plate.DISCUSSIONThe condition occurs when pigments, with or withoutink ingredients, become solubilized or emulsified into the fountainsolution.plate wear, na physical abrading away of th
46、e non-image orimage area, or both, of the plate.DISCUSSIONThis erosion can be caused by abrasive materials in theink or on the substrate.powdering, na condition where ink easily rubs off a printafter the normal drying period.DISCUSSIONAlso referred to as “chalking.” Powdering could be dueto the rapi
47、d absorption of the vehicle into the paper or the improperpigment to binder ratio in the ink.print void, na defective spot of unprinted matter in a printsolid or halftone that can be caused by a buildup of foreignmatter on the plate or blanket.railroad tracks, na pattern on the printed sheet extendi
48、ng inthe machine direction that is comprised of one or more linearregions. TAPPIDISCUSSIONThis effect may be caused by excessive variations indrying across the width of the web.scum, na condition that occurs when a lithographic plate hasbecome sensitized in the non-image areas and these areasbegin t
49、o take ink. GATFset-off, nthe unintentional transfer of part of an image or inkfrom its intended location to another surface. F 425show-through, nthe printed image can be observed on theopposite side of the sheet under normal lighting conditions.DISCUSSIONThis condition can be caused by a heavy ink film, inkstrike-through, or low substrate opacity.slinging, nsee spraying.slip roll ink buildup, nan undesirable accumulation of inkon the dampening rolls of a continuous ty
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