1、Designation: D 7305 08aStandard Test Method forReflection Density of Printed Matter1This standard is issued under the fixed designation D 7305; 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
2、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 densito-meter or spectrodensitometer
3、.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 values rangingfrom j
4、ust 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 regarded asstand
5、ard. 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 determine the appli
6、ca-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 284 Terminology of AppearanceE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ANSI Standards:3CGATS.4-1993 Graphic Technology Graphic Arts Reflec-tion Den
7、sitometry Measurements Terminology, Equa-tions, Image Elements and ProceduresCGATS.6 Graphic Technology Specifications forGraphic Arts PrintingCGATS.11-1999 Graphic Technology Certified Refer-ence Materials for Reflection and Transmission Metrology Documentation Requirements and Recommended Pro-cedu
8、resPH 2.17 Geometric Conditions for Reflection DensityPH 2.18 Spectral Conditions for the Measurement of Opti-cal Density2.3 ISO Standard:3ISO 15790 Graphic technology and photography Certi-fied reference materials for reflection and transmissionmetrology Documentation and procedures for use,includi
9、ng 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 TerminologyE 284.3.2 Terminology specifi
10、c 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 practice of character-iz
11、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, na color having the
12、 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.3.2.6 status T, nan
13、 ISO Reflection Status Density.NOTE 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 efflux1This test method is under the jurisdiction of ASTM Committee
14、 D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.56 on Printing Inks.Current edition approved Nov. 1, 2008. Published November 2008. Originallyapproved in 2008. Last previous edition approved in 2008 as D 7305 - 08.2For referenced AST
15、M 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.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th
16、 Floor, New York, NY 10036, http:/www.ansi.org.1*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.spectrum. Originally, these modifiers were defined by combinations ofWra
17、tten 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 applicable to the measurement ofartwork fo
18、r 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 applied, notably in theUSA, to the meas
19、urement of most other printed graphic arts materials.The status E spectral products are also applicable to the measurement ofgraphics arts materials such as ink-on-paper printed sheets, and off-pressproofs. They evolved from the wider of the two passband filter specifi-cations of DIN 16536-2:1986 fo
20、r the Yellow and the Magenta and Cyanspectral products were chosen to match those of Status T. Status E spectralproducts have been applied, primarily in Europe, to the measurement ofgraphic arts materials. The narrower passband of the Yellow filter(compared to Status T) produces values that are more
21、 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 is calibratedand set for the desired
22、 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 the intensity of the color, colorbal
23、ance 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. This then allows the use of theprint
24、 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 Transfer of density readings from one s
25、et 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 testmethod to use density readings as digital proof of target pointsfor printing process control.7. Apparatus7.1 Densitometer, of which there are two types.FI
26、G. 1 ISO Status Density Spectral ProductsD 7305 08a27.1.1 Reflection Densitometer conforming to ANSI Stan-dard PH 2.17 with a Status T response that conforms to ANSIStandard PH 2.18, and used according to CGATS.4-1993.7.1.2 Spectrodensitometer, with a Status T response thatconforms to ANSI Standard
27、PH 2.18, 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.8. Materials8.1 Reference Standards suc
28、h 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 film orpaper with low opacity, due to show
29、 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 measuredmust be large enough to accommod
30、ate 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 willdecrease with time due to dry back until
31、 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.10.2 Calibrate the instrument according
32、 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. Readings that differ from the labelled valu
33、e 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 Select the filter on the densitometer to m
34、easure 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 producing spectral output is used and
35、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).11.4 Place the densitometer aperture on
36、 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 thelength of the test specimen.11.6 Fo
37、r 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 requirements in Section 12 tocharacteri
38、ze reflection density measurement.12. Report12.1 Report the following information:12.1.1 The manufacturer and model number of the densito-meter or spectrodensitometer.12.1.2 The aperture on the measuring head of the instru-ment.12.1.3 The spectral response (status T).12.1.4 The identity of the backi
39、ng 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 this testmethod was conducted. Ten labora
40、tories tested five specifiedareas of triplicate prints of four colors, measuring status Tdensities. The reflection density of the prints varied fromaround 0.85 on the yellow to about 1.60 on the black. The testresults were analyzed in accordance with Practice E 691. Basedon the statistical analysis
41、of the results, the following criteriashould be 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.4Availabl
42、e from IDEAlliance, 1421 Prince 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
43、the densityof unprinted substrate and subtracting this value.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D011141.D 7305 08a313.1.2 ReproducibilityTwo results, each the mean of fivedeterminations, obtained by operators in di
44、fferent laboratoriesshould be considered suspect if they differ by more than 0.05density units.13.1.3 BiasThere are several sources of bias in theassessment of reflection density of prints. A certified referencematerial (CRM) or materials are required to assess the level ofbias for any given instrum
45、ent. 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 uncertainty at the 23 coveragefor the T- Ref ranges
46、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 instrument reproduc-ibility, taken in quadrature. That is, the square root of the sumof the squares of the
47、uncertainty and the reproducibility. Forthis standard the upper limit on the bias is 0.064 density units.Direct tests of T-Ref versus one of the instruments used in theround-robin gave bias of between 0.00 and 0.05 density unitson the different test targets.14. Keywords14.1 process color; reflection
48、 densitometer; reflection den-sity; spectrodensitometerSUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue(D 7305 - 08) that may impact the use of this standard. (Approved November 1, 2008.)(1) 6.1 was revised.ASTM International takes
49、 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 invited either for revision of this standard or f
