1、Designation: D7305 08a (Reapproved 2013)Standard Test Method forReflection Density of Printed Matter1This standard is issued under the fixed designation D7305; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. 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 test method describes a procedure for measuringreflection density of printed matter using a reflection densitom-eter or spe
3、ctrodensitometer.1.2 This test method is intended primarily for process colors(yellow, magenta and cyan) and black. With appropriateinstrumentation, it may also be used for other colors.1.3 This test method applies to prints made by any printingprocess on a flat surface, with reflection density valu
4、es rangingfrom just above zero, on the unprinted substrate, through toaround 2.5 for very dense prints.1.4 This test method can be used for prints on paper, film orboard but not for those on metal or foil. It can be conducted inthe pressroom or laboratory.1.5 The values stated in SI units are to be
5、regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and det
6、ermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E284 Terminology of AppearanceE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ANSI Standards:3CGATS.4-1993 Graphic Technology Graphic Arts R
7、eflec-tion Densitometry Measurements Terminology,Equations, Image Elements and ProceduresCGATS.6 Graphic Technology Specifications for GraphicArts PrintingCGATS.11-1999 Graphic Technology Certified Refer-ence Materials for Reflection and Transmission Metrology Documentation Requirements and Recommen
8、ded Pro-ceduresPH 2.17 Geometric Conditions for Reflection DensityPH 2.18 Spectral Conditions for the Measurement of OpticalDensity2.3 ISO Standard:3ISO 15790 Graphic technology and photography Certi-fied reference materials for reflection and transmissionmetrology Documentation and procedures for u
9、se,including determination of combined standard uncertainty2.4 Other Standard:3DIN 16536-2:1986 Testing of prints and printing inks ingraphic technology Colour density measurements onon-press or off-press prints3. Terminology3.1 Definitions related to appearance are in TerminologyE284.3.2 Definition
10、s of Terms Specific to This Standard:3.2.1 reflection density, nthe light-absorbing property of amaterial, expressed as the logarithm of the reciprocal of thereflectance factor (i.e. higher density indicates more light isabsorbed). D = log10(1/R) = -log10(R)3.2.2 reflection densitometry, nthe practi
11、ce of characteriz-ing the amount of light absorption of materials by measuringreflectance and calculating and reporting reflection density.3.2.3 spectrodensitometer, na spectrophotometer with ap-propriate software to convert the measured reflectance valuesto reflection density.3.2.4 process color, n
12、a color having the main attribute ofabsorbing approximately one-third (1/3) the visible spectrumand transmitting the other two-thirds (2/3).3.2.5 dry back, nthe reduction in density that occurs overtime after printing on paper and other absorbent substrates dueto ink penetration into the substrate.3
13、.2.6 status T, nan ISO Reflection Status Density.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, andApplications and is the direct responsibility ofSubcommittee D01.56 on Printing Inks.Current edition approved June 1, 2013. Published July 20
14、13. Originally approvedin 2008. Last previous edition approved in 2008 as D7305 08a. DOI: 10.1520/D7305-08AR13.2For 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 s
15、tandards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Bo
16、x C700, West Conshohocken, PA 19428-2959. United States1NOTE 1ISO Reflection Status Density is defined by its SpectralProducts (Fig. 1), that is, the wavelength by wavelength combination of astandard influx spectrum (CIE illuminant A) and the filter-modifed effluxspectrum. Originally, these modifier
17、s were defined by combinations ofWratten filters but today, either more durable materials, such as glass areused or the Spectral Products are computed numerically from tables ofweights and the spectral reflectance factors measured with a spectroden-sitometer.The status T spectral products are applic
18、able to the measurement ofartwork for color separation and graphics arts materials such as ink-on-paper printed sheets, and off-press proofs. Status T was originally definedto closely match the spectral products historically used in evaluatingoriginal artwork to be color separated but were later app
19、lied, notably in theUSA, to the measurement of most other printed graphic arts materials.The status E spectral products are also applicable to the measurementof graphics arts materials such as ink-on-paper printed sheets, andoff-press proofs. They evolved from the wider of the two passband filterspe
20、cifications of DIN 16536-2:1986 for the Yellow and the Magenta andCyan spectral products were chosen to match those of Status T. Status Espectral products have been applied, primarily in Europe, to the measure-ment of graphic arts materials. The narrower passband of the Yellow filter(compared to Sta
21、tus T) produces values that are more similar for all threechromatic inks at typical printing densities.4. Symbols4.1 Symbols: The following symbols are defined or referredto in this standard.D reflection densityR reflectance factor5. Summary of Test Method5.1 The densitometer or spectrodensitometer
22、is calibratedand set for the desired spectral response and color.5.2 Multiple reflection density measurements are taken inspecified positions on the print in order to determine an averageresult.6. Significance and Use6.1 One of the key properties for printing in the lab or onproduction equipment is
23、the intensity of the color, colorbalance and uniformity. This test can be used to ensure that theproper amount of ink is transferred to the substrate byobtaining a target density value, in addition to determiningwhether the print is uniform by measuring the reflectiondensity over a wide print area.
24、This then allows the use of theprint for controlled testing of other appearance properties, suchas gloss and color, and performance properties, such asresistance to abrasion and chemicals.6.2 This test can be used to help achieve consistent colorreproduction of printed color on flat surfaces.6.3 Tra
25、nsfer of density readings from one set of inks toanother, or from one substrate to another, carries a high risk ofproducing a color or tone shift. It is not in the scope of this testFIG. 1 ISO Status Density Spectral ProductsD7305 08a (2013)2method to use density readings as digital proof of target
26、pointsfor printing process control.7. Apparatus7.1 Densitometer, of which there are two types.7.1.1 Reflection Densitometer conforming to ANSI Stan-dard PH2.17 with a Status T response that conforms to ANSIStandard PH2.18, and used according to CGATS.4-1993.7.1.2 Spectrodensitometer, with a Status T
27、 response thatconforms to ANSI Standard PH2.18, calibrated according tothe manufacturers instructions and used according toCGATS.6. A spectrodensitometer that gives spectral output isrequired for non-process colors.7.1.3 Standardization plate and calibration instructionssupplied by the manufacturer.
28、8. Materials8.1 Reference Standards such as the T-Ref standard.48.2 Backing Paper from the print job is normally used in theprinting industry. Matte-black backing paper having a visualreflection density of 1.50 6 0.20 can be used but may not beappropriate for all applications such as transparent fil
29、m orpaper with low opacity, due to show through.9. Test Samples9.1 Test samples may be production prints or prints pre-pared in the laboratory. Many production prints contain colorbars or targets specifically intended for monitoring reflectiondensity. In either case, the area of the specimen to be m
30、easuredmust be large enough to accommodate the aperture of theinstrument being used.9.2 Print areas to be measured must be free of wrinkles,folds, fingerprints and other such defects.9.3 Prints can be measured at any interval after printing.However, on absorbent substrates the density readings willd
31、ecrease with time due to dry back until the ink is fully dry.10. Calibration and Standardization10.1 Warm up the densitometer or spectrodensitometeraccording to the time stated in the manufacturers recommen-dations. Use the first few readings to establish stable readingson the standardization plate.
32、10.2 Calibrate the instrument according to the manufactur-ers procedure.10.2.1 Set the instrument to the specific density valuesestablished by the manufacturer.10.3 Further assurance of calibration precision can be ob-tained by measuring a certified reference material such as theT-Ref standard. Read
33、ings that differ from the labelled value onthe certified reference material by more than the greater of 0.02density units or 2 % should be discussed with the densitometermanufacturer in order to determine whether the particulardensitometer is performing to its design capability.11. Procedure11.1 Sel
34、ect the filter on the densitometer to measure thespecific color.11.1.1 If the test sample is a process color, use the appro-priate status T filter.11.1.2 If the sample is black, gray or white, use the Visualdensity filter.11.1.3 If the sample is a non-process color, a spectrodensi-tometer capable of
35、 producing spectral output is used and thereading is recorded at the wavelength giving the highestreading (maximum absorption).11.2 Set the densitometer to the appropriate mode to mea-sure density.11.3 Place the backing sheet(s) on a flat surface and the printspecimen on top of the backing sheet(s).
36、11.4 Place the densitometer aperture on the test specimen.11.5 For laboratory and production prints containing largesolids, take five measurements, one in each corner 25 mm fromthe edge of the test specimen and one in the middle if the colorspecimen is large enough or five readings representative of
37、 thelength of the test specimen.11.6 For production prints containing only color bars orsmall targets, five measurements can either be taken at theappropriate patches along the color bar or on five sequentialprints specimens.11.7 Calculate the mean and record the reading.11.8 Use the data recording
38、requirements in Section 12 tocharacterize reflection density measurement.12. Report12.1 Report the following information:12.1.1 The manufacturer and model number of the densi-tometer or spectrodensitometer.12.1.2 The aperture on the measuring head of the instru-ment.12.1.3 The spectral response (sta
39、tus T).12.1.4 The identity of the backing paper used.12.1.5 Whether the measurement is absolute density orrelative density.512.1.6 The identity of the prints measured and the measure-ment positions.12.1.7 The interval after printing.13. Precision and Bias613.1 PrecisionAn interlaboratory study of th
40、is test methodwas conducted. Ten laboratories tested five specified areas oftriplicate prints of four colors, measuring status T densities.The reflection density of the prints varied from around 0.85 onthe yellow to about 1.60 on the black. The test results were4Available from IDEAlliance, 1421 Prin
41、ce St., Suite 230, Alexandria, VA223142805.5The default measurement is absolute density which includes the density of thesubstrate. Relative density, which excludes the density of the substrate, can beobtained as a function on most densitometers or by manually measuring the densityof unprinted subst
42、rate and subtracting this value.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D01-1141.D7305 08a (2013)3analyzed in accordance with Practice E691. Based on thestatistical analysis of the results, the following criteria shouldb
43、e used to judge unacceptability of results at the 95 %confidence level:13.1.1 RepeatabilityTwo results, each the mean of fivedeterminations, obtained by the same operator should beconsidered suspect if they differ by more than 0.03 densityunits.13.1.2 ReproducibilityTwo results, each the mean of fiv
44、edeterminations, obtained by operators in different laboratoriesshould be considered suspect if they differ by more than 0.05density units.13.1.3 BiasThere are several sources of bias in the assess-ment of reflection density of prints. A certified referencematerial (CRM) or materials are required to
45、 assess the level ofbias for any given instrument. The creation and use of certifiedreference materials for assessment of printing is documented inANSI CGATS.11-1999 and ISO 15790. The industry standardreference material in the North American printing industry isthe T-Ref standard. The stated uncert
46、ainty at the 2 coveragefor the T- Ref ranges between 60.02 and 60.04 depending onthe value of the density with the most common value being60.04.An upper limit on the bias can be set as the combinationof the uncertainty of the CRM and the instrumentreproducibility, taken in quadrature. That is, the s
47、quare root ofthe sum of the squares of the uncertainty and the reproducibil-ity. For this standard the upper limit on the bias is 0.064 densityunits. Direct tests of T-Ref versus one of the instruments usedin the round-robin gave bias of between 0.00 and 0.05 densityunits on the different test targe
48、ts.14. Keywords14.1 process color; reflection densitometer; reflection den-sity; spectrodensitometerSUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue (D7305 - 08)that may impact the use of this standard. (Approved November 1, 2008.)
49、(1) 6.1 was revised.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are inv
