What is ISO 5631-1 – Determination of the colour of papers and boards about?
ISO 5631-1 is the first part of the multi-series standard that is applicable to paper and board. ISO 5631-1 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 is 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.
Note: ISO 5631-1 is not applicable to coloured papers or boards which incorporate fluorescent dyes or pigments.
Who is ISO 5631-1 - Determination of the colour of papers and boards for?
ISO 5631-1 on the determination of the colour of papers and boards is useful for:
- The graphic arts industry
- The paper and board industry
- Paper mills
- Paper and paperboard manufacturing companies
- Suppliers and distributors for paper and board
- Laboratories for paper and board
- Paper analysis researchers
Why should you use ISO 5631-1 - Determination of the colour of papers and boards?
The colour of an object can be uniquely characterized by means of a triplet of colour coordinates such as the CIE tristimulus values or the CIELAB 1976 L*, a*, b* coordinates for a specified CIE illuminant and CIE standard observer. The light reflected from a sample under specified conditions is analysed either by a tristimulus-filter colourimeter or by an abridged spectrophotometer, and the colour coordinates are then calculated for C/2° conditions.
ISO 5631-1 describes the measurement and description of colour in terms of the CIE illuminant C and the CIE 1931 (2°) standard observer. ISO 5631-1 also describes measurements and calculations carried out in an analogous manner using either the CIE standard illuminant D65 and the CIE 1964 (10°) standard observer or the CIE illuminant D50 and the CIE 1931 (2°) standard observer.
ISO 5631-1 provides you with spectral characteristics of reflectometers for determining tristimulus values. ISO 5631-1 guidelines help you with the comparison of papers in graphic arts situations since these illuminant/observer conditions are used within the graphic arts industry.
What’s changed since the last update?
BS ISO 5631-1:2015 supersedes BS ISO 5631-1:2009, which is withdrawn. BS ISO 5631-1:2015 includes the major change with respect to BS ISO 5631-1:2009 is to allow for calculations using ASTM E308 for instruments that have bandpass correction and still maintain the procedure for instruments without bandpass correction.