ISO/TC 6/WG 3 - Optical properties

ISO 4094:2017 provides both general requirements and specific requirements (Annex A) for laboratories seeking to become "Authorized Laboratories (ALs)" and to maintain their Authorized Laboratory status for the issue of optical reference transfer standards of level 3. This document follows the requirements and adopts the format of ISO/IEC 17025, with the aims of: a) establishing and maintaining international optical reference transfer standards of level 2 (IR2) traceable to an international optical reference primary standard of level 1 (IR1) maintained by a standardizing laboratory; b) distributing traceability required to achieve inter-laboratory agreement in the results of test methods specified in International Standards for optical properties of paper, board or pulp; c) participating in the design and development of new methods and international harmonization of procedures. When a laboratory does not undertake one or more of the activities covered by this document, such as sampling and the design/development of new methods, the requirements of those clauses do not apply. ISO 4094:2017 is for use by specified laboratories authorized to issue optical reference transfer standards in developing their management system for quality, administrative and technical operations. Laboratory customers, regulatory authorities and accreditation bodies can also use it in confirming or recognizing the competence of laboratories. NOTE It might be necessary to explain or interpret certain requirements in this document to ensure that the requirements are applied in a consistent manner. Guidance for consistent application can be obtained from Technical Committee ISO/TC 6.

ISO 9416:2017 specifies a method for the calculation of light-scattering and light-absorption coefficients based upon diffuse reflectance measurements made under the conditions specified in ISO 2469 using the colour matching function ȳ(λ) and CIE illuminant C. It is emphasized that the strict evaluation of the light-scattering and light-absorption coefficients requires conditions which cannot be achieved with the instrumentation specified here. The values obtained by application of this document are dependent on the application of the Kubelka-Munk equations, not to full reflectance data but to reflectance factor data obtained using the specified d/0° geometry and a gloss trap. The use of the method is restricted to white and near-white uncoated papers with an opacity less than about 95 %. Paper that has been treated with a fluorescent dyestuff or that exhibits significant fluorescence can only be dealt with if a filter with a cut-off wavelength of 420 nm is used to eliminate all the fluorescence effect in the UVex(420) mode.

ISO 11475:2017 specifies the procedure to be used for determining the whiteness of papers and boards. The values obtained correspond to the visual appearance of white papers and boards with or without fluorescent whitening agents when they are viewed under the CIE D65 daylight standard illuminant. It is based on reflectance data obtained over the full visible spectral range (VIS) in contrast to the measurement of ISO brightness which is limited to the blue region of VIS. In addition, it specifies a method for adjustment of the UV content to correspond to the CIE D65 daylight illuminant[10][11], insofar as results obtained when fluorescent whitening agents are present are dependent upon the UV content of the radiation falling upon the sample. It is specific for white fluorescent paper samples where the emission due to the fluorescent whitening agent (FWA) occurs in the blue region of the visible spectrum. This method is not applicable to coloured papers containing fluorescent dyes. ISO 11475:2017 should be read in conjunction with ISO 2469. NOTE 1 This document is based on the CIE whiteness formula, published in CIE 15.3-2004[9]. NOTE 2 A related International Standard, ISO 11476, specifying the procedure for obtaining values corresponding to the appearance of these products under indoor illumination, has also been published.

ISO 2470-1:2016 specifies a method for measuring the diffuse blue reflectance factor (ISO brightness) of pulps, papers and boards. ISO 2470-1:2016 is limited in its scope to white and near-white pulps, papers and boards. The measurement can only be made in an instrument in which the ultraviolet energy level of the illumination has been adjusted to correspond to the CIE illuminant C[6] using a fluorescent reference standard. The CIE illuminant C is taken to be representative of indoor daylight conditions because it contains a suitable proportion of UV radiation.[9]

ISO 11476:2016 specifies the procedure to be used for determining the CIE whiteness of papers and boards, in order to obtain values which correspond to the visual appearance of white papers and boards, with or without fluorescent whitening agents, when they are viewed indoors. It is based on radiance factor data obtained over the full visible spectral range (VIS) in contrast to the measurement of ISO brightness, which is limited to the blue region of VIS. It also specifies the procedures for the determination of CIE tint values and the fluorescent component of CIE whiteness. In addition, it specifies a method for adjustment of the UV-content to correspond to that of CIE illuminant C,[10][12] since the results obtained when fluorescent whitening agents are present are dependent upon the UV-content of the radiation falling upon the sample. The CIE illuminant C is taken to be representative of indoor illumination conditions because it contains a suitable proportion of UV radiation.[7] This method is not applicable to coloured papers containing fluorescent dyes. It is specific to the situation where the fluorescence occurs in the blue region of the visible spectral range. ISO 11476:2016 is read in conjunction with ISO 2469.

ISO 8254-2:2016 specifies a photometric test method for the assessment of visual gloss by means of a reflectometer value measured at an angle of 75°. It is applicable to plane paper and board surfaces of gloss levels below 65, measured according to ISO 8254-2:2016. It should be the preferred method for paper and board surfaces of gloss levels below 20, measured according to ISO 8254-2:2016. Materials containing optical brightening agents may be measured.

ISO 8254-3:2016 specifies a method for measuring the specular gloss of paper and board at an angle of 20° to the normal to the paper surface. It is applicable chiefly to highly glossy surfaces, such as cast-coated, lacquered, highly varnished or waxed papers and high-gloss ink films. NOTE This part of ISO 8254 has been developed from TAPPI T653[2], ISO 2813[1] and from ISO 8254‑1.

ISO/TR 10688:2015 provides a summary of the formulae used for determining the optical properties of pulp, paper and board. This Technical Report is to be used in conjunction with the particular International Standards for the determination of the desired optical properties. ISO/TR 10688:2015 provides the information necessary for those involved in development of software for computation of optical properties in accordance with current ISO standards.

ISO 5631-1:2015 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. ISO 5631-1:2015 is not applicable to coloured papers or boards which incorporate fluorescent dyes or pigments. It may be used to determine the colour of papers or boards which contain fluorescent whitening agents provided the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE illuminant C, using a fluorescent reference standard that fulfils the requirements for international fluorescent reference standards of level 3 (IR3) as prescribed by ISO 2469 with an assigned ISO brightness value (C/2°) provided by an authorized laboratory, as described in ISO 2470‑1.

ISO 5631-2:2015 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. It can be used to determine the colour of papers or boards that contain fluorescent whitening agents, provided the UV content of the illumination on the test piece has been previously adjusted to give the calibrated colourimetric value corresponding to CIE standard illuminant D65, using a fluorescent reference standard with an assigned CIE whiteness (D65/10°) value provided by an authorized laboratory, as described in ISO 11475. ISO 5631-2:2015 is not applicable to coloured papers or boards that incorporate fluorescent dyes or pigments.

ISO 5631-3:2015 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. ISO 5631-3:2015 is primarily intended for measuring the colour of paper and board to be used in the graphic arts industry, where that industry specifies the measurement of colour under D50/2° conditions in accordance with ISO 13655. This method differs from ISO 13655, in that the UV content of the illumination is adjusted to a different level. The method can be used to determine the colour of papers or boards that contain fluorescent whitening agents, provided the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE illuminant C, using a fluorescent reference standard that fulfils the requirements for international fluorescent reference standards of level 3 (IR3) as prescribed by ISO 2469 with an assigned ISO brightness value (C/2°) provided by an authorized laboratory, as described in ISO 2470‑1. ISO 5631-3:2015 is not applicable to coloured papers or boards that incorporate fluorescent dyes or pigments.

ISO 2469:2014 describes the general procedure for measuring the diffuse radiance factor of all types of pulp, paper and board. More particularly, it specifies in detail the characteristics of the equipment to be used for such measurements, and the procedures to be used for calibrating that equipment. ISO 2469:2014 may be used to measure the diffuse radiance factors and related properties of materials containing fluorescent whitening agents, provided that the UV-content of the instrument illumination has been adjusted to give the same level of fluorescence as a fluorescent reference standard for a selected CIE illuminant, in accordance with the specific International Standard describing the measurement of the property in question. ISO 2469:2014 describes the preparation of fluorescent reference standards, although the procedures for using these standards are not included, since their use is described in detail in the specific International Standards describing the measurement of the properties of materials containing fluorescent whitening agents.

ISO 22891:2013 specifies a method for the calculation of transmittance based upon diffuse reflectance measurements. The use of the method is restricted to white and near-white translucent papers (see 3.9). If it is necessary to determine the transmittance of papers which contain fluorescent whitening agents, the fluorescence emission is eliminated using the prescribed UV cut-off filter.

ISO 8254-1:2009 specifies a method for measuring the specular gloss of paper at an angle of 75° to the normal to the paper surface. Although its chief application is to coated papers, it may also be used for glossy uncoated papers such as supercalendered papers.

ISO 2471:2008 specifies a method for the determination of the opacity (paper backing) of paper by diffuse reflectance. It can be used to determine the opacity of papers or boards which contain fluorescent whitening agents, provided the UV content of the radiation incident on the test piece has been adjusted to conform to that in the CIE illuminant C using a fluorescent reference standard provided by an ISO/TC 6 Authorized Laboratory as described in ISO 2470-1. ISO 2471:2008 is not applicable to coloured papers or boards which incorporate fluorescent dyes or pigments.

ISO 22754:2008 specifies a method for the determination of the effective residual ink concentration (ERIC number) by infrared reflectance measurement. ISO 22754:2008 is applicable to all types of deinked, recycled pulp and to sheets of machine-made paper made from recycled pulp, where the residual ink is black. The method is applicable to materials available in sheet form only if the opacity at 950 nm is less than 97 %. The ERIC number obtained is dependent on the distribution of ink particle sizes, and the method is most effective for submicron particles. The value obtained is reliable only if the test material is uniform in ink distribution, formation, and grammage such that presenting different parts of the sheet to the measuring aperture of the reflectometer produces very similar readings.

ISO 2470-2:2008 specifies a method for measuring the D65 brightness of pulps, papers and boards. ISO 2470-2:2008 is limited in its scope to white and near-white pulps, papers and boards, particularly those exhibiting fluorescence which promotes the appearance of whiteness. The measurement can only be made in an instrument in which the ultraviolet energy level of the illumination has been adjusted to correspond to the CIE standard illuminant D65 using a fluorescent reference standard. The source employed in ISO 2470-2:2008 excites almost twice as much fluorescence as the illuminant in ISO 2470-1. Consequently, ISO 2470-2:2008 is better suited for measuring the fluorescent contribution to the brightness. However, D65 brightness should not be confused with ISO brightness which closely approximates the brightness of papers viewed under indoor conditions.

ISO 5631-3:2014 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. ISO 5631-3:2014 is primarily intended for measuring the colour of paper and board to be used in the graphic arts industry, where that industry specifies the measurement of colour under D50/2° conditions in accordance with ISO 13655. This method differs from ISO 13655, in that, the UV content of the illumination is adjusted to a different level. The method can be used to determine the colour of papers or boards that contain fluorescent whitening agents, provided the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE illuminant C, using a fluorescent reference standard provided by an authorized laboratory, as described in ISO 2470-1. ISO 5631-3:2014 is not applicable to coloured papers or boards that incorporate fluorescent dyes or pigments.

ISO 5631-2:2014 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. It can be used to determine the colour of papers or boards that contain fluorescent whitening agents, provided the UV content of the illumination on the test piece has been previously adjusted to give the calibrated colourimetric value corresponding to CIE standard illuminant D65, using a fluorescent reference standard with an assigned CIE whiteness (D65/10°) value provided by an authorized laboratory, as described in ISO 11475. ISO 5631-2:2014 is not applicable to coloured papers or boards that incorporate fluorescent dyes or pigments.

ISO 11476:2010 specifies the procedure to be used for determining the CIE whiteness of papers and boards, in order to obtain values which correspond to the visual appearance of white papers and boards, with or without fluorescent whitening agents, when they are viewed indoors. It is based on radiance factor data obtained over the full visible spectral range (VIS) in contrast to the measurement of ISO brightness, which is limited to the blue region of VIS. ISO 11476:2010 also specifies the procedures for the determination of CIE tint values and the fluorescent component of CIE whiteness. In addition, it specifies a method for adjustment of the UV content to correspond to that of CIE illuminant C, since the results obtained when fluorescent whitening agents are present are dependent upon the UV content of the radiation falling upon the sample. The CIE illuminant C is taken to be representative of indoor illumination conditions because it contains a suitable proportion of UV radiation. This method is not applicable to coloured papers containing fluorescent dyes. It is specific to the situation where the fluorescence occurs in the blue region of the visible spectral range. ISO 11476:2010 is read in conjunction with ISO 2469.

ISO 5631-1:2009 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. ISO 5631-1:2009 is not applicable to coloured papers or boards which incorporate fluorescent dyes or pigments. It may be used to determine the colour of papers or boards which contain fluorescent whitening agents provided the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE illuminant C, using a fluorescent reference standard provided by an ISO/TC 6 authorized laboratory, as described in ISO 2470-1.

ISO 2470-1:2009 specifies a method for measuring the diffuse blue reflectance factor (ISO brightness) of pulps, papers and boards. ISO 2470-1:2009 is limited in its scope to white and near-white pulps, papers and boards. The measurement can only be made in an instrument in which the ultraviolet energy level of the illumination has been adjusted to correspond to the CIE illuminant C using a fluorescent reference standard.

ISO 9416:2009 specifies a method for the calculation of light-scattering and light-absorption coefficients based upon diffuse reflectance measurements made under the conditions specified in ISO 2469 using the colour matching function and CIE illuminant C. It is emphasized that the strict evaluation of the light-scattering and light-absorption coefficients requires conditions which cannot be achieved with the instrumentation specified here. The values obtained by application of ISO 9416:2009 are dependent on the application of the Kubelka-Munk equations, not to full reflectance data but to reflectance factor data obtained using the specified d/0° geometry and a gloss trap. The use of the method is restricted to white and near-white uncoated papers with an opacity less than about 95 %. Paper that has been treated with a fluorescent dyestuff or that exhibits significant fluorescence can only be dealt with if a filter with a cut-off wavelength of 420 nm is used to eliminate all the fluorescence effect in the UVex(420) mode.

ISO 5631-2:2008 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. It may be used to determine the colour of papers or boards that contain fluorescent whitening agents, provided the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE standard illuminant D65, using a fluorescent reference standard with an assigned CIE whiteness (D65/10°) value provided by an ISO/TC 6 authorized laboratory, as described in ISO 11475. ISO 5631-2:2008 is not applicable to coloured papers or boards that incorporate fluorescent dyes or pigments.

ISO 5631-3:2008 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. ISO 5631-3:2008 is primarily intended for measuring the colour of paper and board to be used in the graphic arts industry where that industry specifies the measurement of colour under D50/2° conditions in accordance with ISO 13655. The method may be used to determine the colour of papers or boards that contain fluorescent whitening agents, provided the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE illuminant C, using a fluorescent reference standard provided by an authorized laboratory, as described in ISO 2470-1. ISO 5631-3:2008 is not applicable to coloured papers or boards that incorporate fluorescent dyes or pigments.

ISO 22891:2007 specifies a method for the calculation of transmittance based upon diffuse reflectance measurements. The use of the method is restricted to white and near-white translucent papers. If it is necessary to determine the transmittance of papers which contain fluorescent whitening agents, the fluorescence emission is eliminated using the prescribed UV cut-off filter.

ISO 2469:2007 describes the general procedure for measuring the diffuse radiance factor of all types of pulp, paper and board. More particularly, it specifies in detail in Annex A the characteristics of the equipment to be used for such measurements, and in Annex B the procedures to be used for calibrating that equipment. ISO 2469:2007 may be used to measure the radiance factors and related properties of materials containing fluorescent whitening agents, provided that the UV radiation content in the illumination has been adjusted to the level specified in the specific International Standard describing the measurement of the property in question. ISO 2469:2007 describes in Annex C the preparation of fluorescent reference standards, although the procedures for using these standards are not included, since their use is described in detail in the specific International Standards describing the measurement of the properties of materials containing fluorescent whitening agents.

ISO 11475:2004 specifies the procedure to be used for determining the whiteness of papers and boards. The values obtained correspond to the visual appearance of white papers and boards with or without fluorescent whitening agents when they are viewed under the CIE D65 daylight illuminant. It is based on reflectance data obtained over the full visible spectral range (VIS) in contrast to the measurement of ISO brightness which is limited to the blue region of VIS. In addition, it specifies a method for adjustment of the UV-content to correspond to the D65 daylight illuminant , insofar as results obtained when fluorescent whitening agents are present are dependent upon the UV-content of the radiation falling upon the sample. It is specific for the measurement of fluorescence in the blue region of the spectrum. This method is not applicable to coloured papers containing fluorescent dyes. It should be read in conjunction with ISO 2469.

ISO 8254-3:2004 specifies a method for measuring the specular gloss of paper and board at an angle of 20° to the normal to the paper surface. It is applicable chiefly to highly glossy surfaces, such as cast-coated, lacquered, highly varnished or waxed papers and high-gloss ink films.

ISO 8254-2:2003 specifies a photometric test method for the assessment of visual gloss by means of a reflectometer value measured at an angle of 75 degrees. It is applicable to plane paper and board surfaces of low gloss, commonly called matt papers and boards having reflectance values, measured according to ISO 8254-2:2003, between 0 and approximately 20. Materials containing optical brightening agents may be measured.

Cancels and replaces the second edition (1977). Specifies the equipment for measuring the diffuse reflectance factor of pulp, paper and board and the procedures for calibrating that equipment. Measurements are used for the evaluation of optical properties such as diffuse blue reflectance factor, the scattering coefficient of pulp, opacity, whiteness, luminous reflectance factor, the chromaticity coordinates of paper and the intrinsic reflectance factor of non-fibrous materials. Numerical values optically characterizing the materials are calculated specifically for each property determined.