1、BRITISH STANDARD BS ISO 2846-4:2000 Graphic technology Colour and transparency of printing ink sets for four-colour printing Part 4: Screen printing ICS 87.080 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS ISO 2846-4:2000 This British Standard, having been prepared under t
2、he direction of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 22 March 2002 BSI 22 March 2002 ISBN 0 580 39300 3 National foreword This British Standard reproduces verbatim ISO 2846-4:2000 and imp
3、lements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee PAI/43, Graphic technology, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The Br
4、itish Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A Brit
5、ish Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present t
6、o the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an insid
7、e front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 12, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsReference number ISO 2846-4:2
8、000(E) INTERNATIONAL STANDARD ISO 2846-4 First edition 2000-12-15 Graphic technology Colour and transparency of printing ink sets for four-colour-printing Part 4: Screen printing Technologie graphique Couleur et transparence des gammes dencre dimpression en quadrichromie Partie 4: SrigraphieISO 2846
9、-4:2000(E) ii ISO 2846-4:2000(E)iii Contents Page Foreword.iv Introduction.v 1 Scope 1 2 Normative references 1 3 Terms and definitions .1 4 Test method2 4.1 Principle2 4.2 Test print preparation2 4.3 Colour measurement procedure 3 5 Colour and transparency 3 5.1 Conformance3 5.2 Colorimetric values
10、3 5.3 Transparency characteristics.4 Annex A (normative) Reference substrate .5 Annex B (informative) Spectral data6 Annex C (informative) Colorimetric values for non-normative conditions .9 Annex D (informative) Detailed explanation of test method, including examples .10 Bibliography12ISO 2846-4:20
11、00(E) iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards 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
12、which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on al
13、l matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International S
14、tandard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this part of ISO 2846 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International
15、 Standard ISO 2846-4 was prepared by Technical Committee ISO/TC 130, Graphic technology. 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
16、printing Part 2: Coldset offset lithographic printing Part 3: Publication gravure printing Part 4: Screen printing Part 5: Flexographic printing Annex A forms a normative part of this part of ISO 2846. Annexes B, C and D are for information only.ISO 2846-4:2000(E)v Introduction The demand for the sc
17、reen printing process to become more consistent and predictable has required a means of standardizing the product to ensure the easy flow of business between the various parties involved in its production. An essential component in this process are the colorimetric characteristics of the ink set. If
18、 a set of standard four-colour process inks suitable for screen printing is to be produced it is necessary to specify a number of parameters. It is the purpose of this part of ISO 2846 to describe those parameters which affect the colorimetric characteristics in such a manner that a standard set of
19、inks can be supplied by any ink manufacturer to any printer who can then supply prints to a Print Buyer with confidence in the colour of the work produced. This part of ISO 2846 will allow screen printers to obtain different sets of inks which will produce a similar colour when printed on the same s
20、ubstrate (paper, board, plastic or fabric etc.). In addition, it will allow colour separations for screen printing to be based on known colour standards. The colorimetric characteristics specified may only be obtained when the inks are printed on the reference substrate. However, similarity of two i
21、nks on a reference substrate will ensure similarity on another substrate.INTERNATIONAL STANDARD ISO 2846-4:2000(E)1 Graphic technology Colour and transparency of printing ink sets for four-colour-printing Part 4: Screen printing 1 Scope This part of ISO 2846 specifies the colour and transparency to
22、be produced by a process colour ink set, including extender, intended for four-colour screen printing when printed under specified screen printing conditions. It also describes the test method to ensure conformance. This part of ISO 2846 is applicable to screen inks for conventional drying and for r
23、adiation curing. This part of ISO 2846 does not specify pigments (or spectral reflectance) 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 Normati
24、ve references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of ISO 2846. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on t
25、his part of ISO 2846 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid I
26、nternational Standards. ISO 535:1991, Paper and board Determination of water absorptiveness Cobb method. ISO 536:1995, Paper and board Determination of grammage. ISO 2144:1997, Paper, board and pulps Determination of residue (ash) on ignition at 900 C. ISO 6588:1981, Paper, board and pulps Determina
27、tion of pH of aqueous extracts. ISO 8254-1:1995, Paper and board Measurement of specular gloss Part 1: 75 gloss with a converging beam, TAPPI method. ISO 8791-4:1992, Paper and board Determination of roughness/smoothness (air leak methods) Part 4: Print- surf method. ISO 13655:1996, Graphic technolo
28、gy Spectral measurement and colorimetric computation for graphic arts images. 3 Terms and definitions For the purposes of this part of ISO 2846, the following terms and definitions apply.ISO 2846-4:2000(E) 2 3.1 extension addition of a transparent material (colorant-free ink) to the ink to reduce th
29、e pigment concentration without significantly influencing the rheological properties of the ink 3.2 press-ready ink ink that has all necessary components and is at press viscosity 3.3 transparency ability of an ink film to transmit and absorb light without scattering NOTE It is generally expressed a
30、s some measure of the unwanted scattering. 4 Test method 4.1 Principle Each ink shall be printed on the reference substrate described in annex A at a range of colorations obtained by varying the extension of the press-ready ink. The colours which result shall be measured colorimetrically and the col
31、our difference between the sample and the pertinent value in Table 1 shall be plotted versus the percentage of press-ready ink. If one or more samples conform to the values and tolerances specified, and the ink, except black, also meets the transparency criteria, that ink complies to this part of IS
32、O 2846. Transparency T shall be evaluated by printing or applying each of the chromatic process inks on a black substrate at a range of ink extensions. The CIELAB colour difference E* ab shall be determined for each sample, between the overprinted and unprinted black. The linear regression coefficie
33、nt (slope of the regression line) between the percentage by mass of press-ready ink in each of the extended ink samples being tested and colour difference shall be calculated from a plot of E* ab versus percentage press-ready ink over a range of extensions. An ink conforms to this requirement if the
34、 transparency T which is the reciprocal of the regression coefficient is negative or greater than the value specified. For further details, see annex D. 4.2 Test print preparation 4.2.1 Prints for colorimetric evaluation For each ink to be evaluated, prepare an extension series with 50 %, 60 %, 70 %
35、, 80 %, 90 % and 100 % of press- ready ink using extender diluted to press viscosity. Apply the series of extended inks to the reference substrate specified in annex A with a method that produces an even ink film thickness. Examples are printing with a flat-bed screen press or coating applicator. Th
36、e wet ink film thickness used for the extension series shall be approximately equal. The method chosen shall produce a curve that shows a pronounced minimum or a data point which is in conformance with Table 1 when E* ab is plotted versus percentage of press-ready ink. If the extension series does n
37、ot produce such a curve, produce another series of specimens with different ink film thicknesses. Produce a higher ink film thickness if the colour difference decreases with increasing percentage of press-ready ink. Produce a lower ink film thickness if the colour difference decreases with decreasin
38、g percentage of press-ready ink. See annex D for further information. 4.2.2 Prints for transparency evaluation Test prints for transparency evaluation shall be produced by printing or applying the inks to be tested over black. The black shall have a lightness (L*) less than six when determined in ac
39、cordance with ISO 13655.ISO 2846-4:2000(E)3 One appropriate substrate is the contrast card 1) . Prior to applying the chromatic ink the CIELAB-values of the black substrate are measured. The ink to be tested shall then be applied on the substrate such that a range of samples is achieved, each with a
40、 different percentage of press-ready ink. 4.2.3 Drying of test prints Prior to colour measurement all samples shall be thoroughly dried using a method simulating the production printing conditions. 4.3 Colour measurement procedure Test prints shall be measured in accordance with ISO 13655, except th
41、at a substrate backing consisting of at least three sheets of the unprinted reference substrate in accordance with annex A shall be used. NOTE The samples are measured spectrally, with a 0/45 or 45/0 geometry instrument. Calculation of CIELAB values and colour differences is performed in accordance
42、with ISO 13655 using tristimulus values which are computed from the spectral data using the CIE 1931 (2) standard colorimetric observer data together with CIE illuminant D 50. 5 Colour and transparency 5.1 Conformance For an ink to conform to this part of ISO 2846, it shall meet the specification fo
43、r colour given in 5.2 at some percentage of press-ready ink and the specification for transparency specified in 5.3. 5.2 Colorimetric values To meet the specification for colour, an ink shall produce a colour that falls within the colour difference tolerances from the specified colorimetric values g
44、iven in Table 1, when printed as specified in 4.2.1 at some percentage of press-ready ink. NOTE 1 The aim values and tolerances given in Table 1 are consistent with those for offset printing, as defined in ISO 2846-1, and may therefore only be strictly applicable to screen printing inks based on sim
45、ilar pigments. For some applications screen printing inks may need to be based on different pigments and while in such circumstances the aim values are the same, the tolerances may need to be larger. NOTE 2 Unlike some other parts of ISO 2846, this part does not specify limits for concentration or i
46、nk film thickness within which to meet the specified colour and tolerances, as such requirements are not applicable to the screen printing process. NOTE 3 Typical spectral data for inks conforming to this part of ISO 2846 are provided in annex B. Reference spectral data for 8 o /diffuse or diffuse/8
47、 o (specular included) geometry are also included in annex B. NOTE 4 Data for CIELAB values calculated from the CIE 1931 (2) standard colorimetric observer, together with CIE standard illuminant D 65, are included in annex C for both geometries. CIELAB data for 8 o /diffuse or diffuse/8 o (specular
48、included) geometry and illuminant D 50 are also included in that annex. 1) Leneta paper or card (No. 105C) which can be purchased from Leneta Corp. Mahwah, N.J., USA. Leneta paper or card is the trade name of a product supplied by Leneta Corporation. This information is given for the convenience of
49、the users of this part of ISO 2846 and does not constitute an endorsement by ISO of the product named. Equivalent products may be used if they can be shown to lead to the same results.ISO 2846-4:2000(E) 4 Table 1 Colorimetric values for 0/45 and 45/0 geometry, illuminant D 50 ,2 observer CIELAB values a Tolerances Ink L* a* b* E* ab L* a* b* Yellow 91,0 5,1 95,0 6,0 Magenta 50,0 76,0 3,0 7,0 Cyan 57,0 39,2 46,0 5,0 Black 18,0 0,8 0,56 0,0 b 18,0 1,5 3,0 a See 4.3. b This me
