kSIST FprEN ISO 787-1:2026

kSIST FprEN ISO 787-1:2026 is a standard for comparing the colour of a coloured pigment with an agreed sample. It is used in pigments and extenders work, mainly where laboratories, manufacturers, or buyers need a repeatable way to check whether two pigment pastes match. The document specifies a general test method, and it treats the automatic muller procedure as the reference method.

What does kSIST FprEN ISO 787-1:2026 specify?

kSIST FprEN ISO 787-1:2026 specifies a general method of test for colour comparison of pigments. The document covers how to prepare the pigment dispersion, how to compare the colour with an agreed sample, and what to record in the test report.

The document is organized into:

• Clause 1 - Scope
• Clause 2 - Normative references
• Clause 3 - Terms and definitions
• Clause 4 - Apparatus and materials
• Clause 5 - Sampling
• Clause 6 - Procedure for sample generation
• Clause 7 - Colour comparison
• Clause 8 - Test report

What are the key requirements of kSIST FprEN ISO 787-1:2026?

Sampling and binder selection

kSIST FprEN ISO 787-1:2026 requires a representative pigment sample, taken in accordance with ISO 15528. It also requires the binder to be agreed between the interested parties.

In practice, this matters because the colour result depends on the sample and on the medium used to disperse the pigment. If no binder is agreed, the standard points to refined linseed oil complying with ISO 150. That gives users a default material when they have not already fixed one in a specification or contract.

Preparing the test and agreed samples

kSIST FprEN ISO 787-1:2026 gives two preparation routes in Clause 6 - one using an automatic muller and one using a hand muller or palette knife. The automatic muller procedure is the reference method.

The two pastes - the test portion and the agreed sample - have to be prepared in the same way and to equivalent consistency. In practice, this keeps preparation variables from hiding or exaggerating a colour difference.

Automatic muller procedure

kSIST FprEN ISO 787-1:2026 specifies the automatic muller route as the reference procedure for sample generation. It calls for weighing the test portion to the nearest 1 mg, mixing it with binder, and grinding it in stages on the muller plates.

This means the user must control the grinding conditions and keep them the same for both the test pigment and the agreed sample. The applied force and the number of stages depend on the pigment, but they must be the same for the two pastes being compared.

Hand muller or palette knife procedure

kSIST FprEN ISO 787-1:2026 also allows preparation on a glass or marble plate with a hand muller or palette knife. The test portion is weighed to the nearest 1 mg, mixed with binder, rubbed out, gathered up, and rubbed again until homogeneous.

This alternative gives a practical route where an automatic muller is not used. The important point is consistency: the same rubbing-out style and paste condition must be used for the agreed sample as for the test sample.

Colour comparison

kSIST FprEN ISO 787-1:2026 requires the two prepared pastes to be spread as opaque strips on a suitable substrate and compared immediately after application. Visual comparison is made in diffuse daylight, with artificial daylight preferred, using ISO 3668.

The standard also allows a colorimeter by agreement between the interested parties. In that case, the procedure follows ISO 18314-1, with colour differences calculated using ISO/CIE 11664-4, and total colour difference reported using ISO/CIE 11664-6 or ISO 18314-5.

Test reporting

kSIST FprEN ISO 787-1:2026 requires the test report to identify the pigment, state the binder and procedure used, describe the colour-comparison method, and record the result as equal to or different from the agreed sample. If a colorimeter is used, the report also includes the colour differences in hue, chroma, and lightness.

What terms does kSIST FprEN ISO 787-1:2026 define?

• Agreed sample - the reference pigment sample used for the colour comparison.
• Binder - the medium mixed with the pigment to form the paste for testing.
• Automatic muller - the grinding device used for the reference preparation method.
• Hand muller - the manual device used to rub out the pigment paste on a plate.
• Substrate - the surface on which the two prepared strips are spread for comparison.
• Colorimeter - an instrument used, by agreement, to measure colour differences instead of relying only on visual assessment.
• Hue, chroma and lightness - the colour components used for describing and reporting colour differences.

Who uses kSIST FprEN ISO 787-1:2026?

kSIST FprEN ISO 787-1:2026 is used by pigment manufacturers, extender suppliers, paint and varnish laboratories, and quality-control teams. It is also relevant to buyers and specifiers who need to compare a delivered pigment against an agreed reference sample.

The standard supports routine product matching, incoming inspection, release testing, and dispute checks when a colour difference has to be assessed in a controlled way.

What changed in kSIST FprEN ISO 787-1:2026 from the previous edition?

This second edition cancels and replaces ISO 787-1:1982, which it says was technically revised. The changes stated in the document are:

• Clause 3 on terms and definitions was added
• the colorimeter method was added in Clause 7
• the normative references were updated

The scope also notes replacement of ISO/R 787/1:1968.

Which standards are used with kSIST FprEN ISO 787-1:2026?

• ISO 150 - gives the specification for the refined linseed oil used when no binder is agreed.
• ISO 15528 - provides the sampling method for taking a representative pigment sample.
• ISO 3668 - gives the visual colour comparison procedure for paints, which this standard uses for strip comparison.
• ISO 18314-1 - sets the practical procedure for instrumental colour measurement.
• ISO 18314-5 - supports colorimetric determination of colour differences in equidistant colour spaces.
• ISO 18451-1 - supplies the general terminology used for pigments, dyestuffs and extenders.
• ISO/CIE 11664-4 - defines the CIE 1976 Lab* colour space used for calculating colour differences.
• ISO/CIE 11664-6 - gives the CIEDE2000 colour-difference formula.

What does the kSIST FprEN ISO 787-1:2026 document contain?

The document contains apparatus requirements, including the muller, palette knife, substrate, burette, and binder arrangement. It gives two full sample-preparation procedures, one for the automatic muller and one for the hand muller or palette knife.

It also provides the colour-comparison method, both visual and instrumental, and a test-report checklist. For users, that means the standard is not just a definition of colour comparison - it is a practical test method covering sample preparation, comparison conditions, and reporting.