1、 Reference numberISO 2846-1:2006(E)ISO 2006INTERNATIONAL STANDARD ISO2846-1Second edition2006-11-15Graphic technology Colour and transparency of printing ink sets for four-colour printing Part 1: Sheet-fed and heat-set web offset lithographic printing Technologie graphique Couleur et transparence de
2、s gammes dencre dimpression en quadrichromie Partie 1: Impression lithographique offset sur feuilles et chaud ISO 2846-1:2006(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless
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7、d in Switzerland ii ISO 2006 All rights reservedISO 2846-1:2006(E) ISO 2006 All rights reserved iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Test method. 2 4.1 Procedure 2 4.2 Test print preparation. 2 4.3 Colour measurement procedures . 3 5 Requir
8、ements for colour, transparency and ink film thickness range 4 5.1 General. 4 5.2 Colorimetric values. 4 5.3 Transparency characteristics 4 5.4 Ink film thickness 4 Annex A (normative) Reference substrate 5 Annex B (informative) Extended explanation of the test procedures, including examples . 6 Ann
9、ex C (informative) Spectral data. 10 Annex D (informative) Tristimulus values for 8:di geometry and illuminant D65 13 Bibliography . 15 ISO 2846-1:2006(E) iv ISO 2006 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards
10、bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizat
11、ions, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in th
12、e ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of
13、the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 2846-1 was prepared by Technical Committee ISO/TC 130, Graphic
14、technology. This second edition cancels and replaces the first edition (ISO 2846-1:1997), of which subclauses 4.2 and 5.2 and Annex D have been technically revised. Some very minor changes have been made for the purposes of simplification, and an effort has been made to clarify and update this docum
15、ent in some places. Clauses 4 and 5 have been interchanged with each other. In addition, the test-print preparation requirements have been deleted and referenced to ISO 2834-1. Annex B, describing the history of the development of the colour standard, has been removed and Annex E relettered to Annex
16、 B. ISO 2846 consists of the following parts, under the general title Graphic technology Colour and transparency of printing ink sets for four-colour printing: Part 1: Sheet-fed and heat-set web offset lithographic printing Part 2: Coldset offset lithographic printing Part 3: Publication gravure pri
17、nting Part 4: Screen printing Part 5: Flexographic printing ISO 2846-1:2006(E) ISO 2006 All rights reserved vIntroduction This part of ISO 2846 defines the colour and transparency of lithographic printing inks. Different sets of inks (both for proof and production printing) conforming to this part o
18、f ISO 2846 will produce a similar colour when printed on the same substrate at the appropriate film thickness. This enables colour separations for offset-lithographic printing to be based on known colour references and simplifies the task of consistently printing the same images in multiple printing
19、 sites. It should be noted that the colorimetric characteristics specified can only be obtained when the inks are printed on the reference substrate. However, the similarity of two inks on a reference substrate generally ensures similarity on another substrate, and it is this similarity that has ena
20、bled industry specifications or standards such as ISO 12647-2 1, which specifies the colour of these inks on other substrates, to be developed. The colour specified in the previous edition of this part of ISO 2846 was based on extensive measurements of commercial ink sets made in Europe, Japan and t
21、he USA. A working group of ISO/TC 130 process control and material experts examined data sets from various countries at the time that edition was prepared and found that a single set of colour coordinates could adequately represent all three proposals within reasonable tolerances. In addition, they
22、found that the transparency of various inks could also be adequately represented by a new method of evaluation. A review undertaken prior to the revision of this edition suggested that there had been little change in the colour and transparency of the inks commercially available and that the charact
23、eristics specified in this part of ISO 2846 could be reconfirmed. INTERNATIONAL STANDARD ISO 2846-1:2006(E) ISO 2006 All rights reserved 1Graphic technology Colour and transparency of printing ink sets for four-colour printing Part 1: Sheet-fed and heat-set web offset lithographic printing 1 Scope T
24、his part of ISO 2846 specifies the colour and transparency characteristics that have to be met by each ink in a process colour ink set intended for proof and production printing using offset lithography. The specified printing conditions (which use a laboratory printability tester), the defined subs
25、trate and a method for testing to ensure conformance are also defined. Characteristics are specified for inks used for sheet-fed, heat-set web and radiation-curing processes. This part of ISO 2846 does not apply to fluorescent inks and it does not specify pigments (or spectral characteristics except
26、 informatively) in order not to preclude developments which may enable different pigment combinations to be used advantageously while still achieving the colorimetric requirements specified in this part of ISO 2846. 2 Normative references The following referenced documents are indispensable for the
27、application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 535, Paper and board Determination of water absorptiveness Cobb method ISO 536, Paper and board Determinat
28、ion of grammage ISO 2144, Paper, board and pulps Determination of residue (ash) on ignition at 900 C ISO 2834-1, Graphic technology Laboratory preparation of test prints Part 1: Paste inks ISO 6588-1, Paper, board and pulps Determination of pH of aqueous extracts Part 1: Cold extraction ISO 8254-1,
29、Paper and board Measurement of specular gloss Part 1: 75 gloss with a converging beam, TAPPI method ISO 8791-4, Paper and board Determination of roughness/smoothness (air leak methods) Part 4: Print-surf method ISO 13655, Graphic technology Spectral measurement and colorimetric computation for graph
30、ic arts images ANSI CGATS.5:2003, Graphic technology Spectral measurement and colorimetric computation for graphic arts images ISO 2846-1:2006(E) 2 ISO 2006 All rights reserved3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 standard ink ink i
31、ntended for four-colour printing which, when printed on the reference substrate and within the applicable range of ink film thicknesses, complies to the colorimetric and transparency specifications of this part of ISO 2846 3.2 transparency ability of an ink film to transmit light NOTE It is generall
32、y expressed as some measure of the unwanted scattering. 3.3 transparency measurement value T reciprocal of the slope of the regression line between ink film thickness and colour difference for overprints of chromatic inks over black substrate 4 Test method 4.1 Procedure Colorimetric conformance shal
33、l be verified by printing each ink on the reference substrate, described in Annex A, at a range of ink film thicknesses. The colours of the resultant test prints shall be measured and the colour difference determined between the sample and the pertinent value given in Table 1. If at least one of the
34、se samples has a smaller colour difference than that specified in 5.2, the ink conforms colorimetrically to this part of ISO 2846. NOTE It is often more convenient to determine the colorimetric conformance of an ink graphically. This is achieved by calculating the colour difference (E*ab) from the v
35、alues in Table 1 for each of the prints made and plotting this against the ink film thickness. The ink conforms if the resultant curve shows a pronounced minimum which is below the E*abvalue specified in Table 1. (See Annex B for further information.) Transparency value, T, shall be determined by pr
36、inting each of the chromatic process inks on to a black substrate meeting the requirements of 4.2.2, at a range of ink film thicknesses. The colour difference, E*ab, is determined for each sample between the overprinted and unprinted black substrate. The gradient of the linear regression of ink film
37、 thickness on colour difference shall be determined. An ink conforms to the transparency requirements of this part of ISO 2846 if the reciprocal of the gradient is negative, or greater than the value specified. (See Annex B for further information.) The gradient of the regression equation may be det
38、ermined directly from the data obtained. However, it is recommended that it be obtained from a graphical plot of the values of E*abagainst ink film thickness. Such a plot enables any unexpected characteristics of the data to be easily visualised. (See Annex B for further information.) If one or more
39、 printed samples of each ink conform to the colorimetric values within the tolerances specified, and the ink also meets the transparency criteria, that ink can be said to comply to this part of ISO 2846. 4.2 Test print preparation 4.2.1 Prints for colorimetric evaluation For each of the inks to be e
40、valuated, a number of test prints shall be made, each produced at a different ink film thickness, according to the conditions specified in ISO 2834-1. ISO 2846-1:2006(E) ISO 2006 All rights reserved 3They shall be made on the reference substrate specified in Annex A. The range of ink film thicknesse
41、s produced shall encompass that specified for the process for which the ink is intended. (See 5.4.) 4.2.2 Prints for transparency evaluation The test prints for transparency evaluation shall be produced by printing the inks to be tested on a black substrate such that a minimum of four samples is ach
42、ieved, each with a different ink film thickness. The printing shall be undertaken as described in ISO 2834-1. The range of ink film thicknesses achieved should at least cover that defined in 5.4. The black substrate shall have a lightness, L*, less than 6 when determined in accordance with ISO 13655
43、 (with the exception that a white backing shall be used when measuring the print; see 4.3). Although in principle it is possible for the user to produce, themselves, the black substrate by printing, it is difficult to ensure that the lightness is sufficiently low without adversely affecting the glos
44、s and printing properties of the substrate. It is usually preferable to use a black substrate or a substrate pre-printed commercially. However, if it is necessary to print the black, the recommendations given in Annex B should be followed. Appropriate substrates are the contrast card or the contrast
45、 strip 1). 4.2.3 Drying of test prints Prior to colour measurement, all samples shall be thoroughly dry. Inks formulated for oxidation drying shall be left for at least 24 h, those formulated for radiation curing shall be dried with an appropriate radiation source within the appropriate time and hea
46、t-set inks shall be heat dried with appropriate drying equipment. NOTE Be aware that the appropriate time for radiation curing inks can be down to parts of a second only. 4.3 Colour measurement procedures Test prints shall be measured in accordance with ISO 13655, except that a white backing which i
47、s in conformance with ANSI CGATS.5 shall be used. Conforming to ISO 13655 means that samples shall be measured spectrally, with a 0:45a or 45a:0 geometry instrument, and for calculation of CIELAB colour values the CIE 1931 (2) standard colorimetric observer data is used together with CIE standard il
48、luminant D50; see Reference 3. Where spectral data is obtained at wavelength intervals greater than 5 nm, the weighting functions for the standard colorimetric observer specified in ISO 13655 are used. For calculating the colour difference from the reference values, the CIE 1976 colour difference, E
49、*ab, shall be used. NOTE 1 ISO 13655 is currently under revision and it is the intent of the committee to add a white backing condition identical to that of ANSI CGATS.5. NOTE 2 For the comparison of measurements, it is useful to record the following details: the ink designation and batch number; the ink layer thicknesses; the substrate used; the printability tester used and the settings used on the tester (speed, force, printing forme); environmental conditions (lab temper
