ASTM_D_6488_-_08_2013.pdf

Designation:D648808(Reapproved 2013)Standard Terminology Relating toPrint Problems1This standard is issued under the fixed designation D6488;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 indicates 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 combinations 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:2D4361 Test Method for Apparent Tack of Printing Inks andVehicles by a Three-Roller TackmeterF425 Terminology Relating to Lithographic Copy Products(Withdrawn 2003)33.Significance and Use3.1 A common set of definitions is essential to improvecommunication and avoid misunderstanding among inkmakers,substrate makers,and printers.3.2 The term“paper”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:blistering,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 sheets 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 sometimes ap-pears 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 selective 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.GATFDISCUSSIONThis 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 may 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 imagesslightly 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 dot 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 thatcontrol dot gain on press are ink film thickness,amount of water feed,solid print density,ink holdout/absorbance characteristics of the paper,1This terminology is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.56 on Printing Inks.Current edition approved June 1,2013.Published July 2013.Originally approvedin 1999.Last previous edition approved in 2008 as D6488 08.DOI:10.1520/D6488-08R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 screen ruling,blanket release,pressure between the blanket and plate,and pressure between the blanket and paper.Optical dot gain resultsfrom light scattering in the paper.The dot gain value can be determinedusing a dosimeter that calculates