Link points to Internet Archive / others. Not hosted by InfraLens. Details
IS 101:1986 Part 2/Sec 1 is the Indian Standard (BIS) for methods of sampling and test for paints, varnishes and related products: part 2 optical properties section 1 colour. This section of IS 101 specifies the testing procedures to evaluate the optical properties, specifically the colour, of paints and varnishes. Engineers and quality control inspectors use this code to determine whether a cured paint film visually matches a specified standard colour (typically from IS 5) under standardized lighting conditions.
Specifies methods for determining the colour of paints, varnishes, and related products by visual comparison and instrumental methods.
Overview
Status
Current
Usage level
Specialized
Domain
Materials Science — Painting, Coatings and Surface Finishing
! Visual colour assessment should always be performed under standard daylight conditions or in a standardized colour matching cabinet (D65 light) to prevent metamerism.
! Always ensure the paint film is completely dry before evaluating its final colour, as wet and dry paint colours often differ significantly.
! Avoid direct glare during inspection by viewing the panel at an angle of 45 degrees rather than straight on.
paintsvarnishescoatingsenamels
International Equivalents
Similar International Standards
ISO 15528:2020ISO (International Organization for Standardization)
HighCurrent
Paints, varnishes and raw materials for paints and varnishes — Sampling
Directly corresponds to the sampling procedures for liquid paints described in IS 101.
ISO 1513:2022ISO (International Organization for Standardization)
HighCurrent
Paints and varnishes — Examination and preparation of test samples
Covers the examination and preparation of samples for testing, equivalent to clauses 3 & 4 of the IS code.
ISO 1514:2022ISO (International Organization for Standardization)
HighCurrent
Paints and varnishes — Standard panels for testing
Details the requirements for standard test panels, equivalent to clause 5 of the IS code.
ASTM D3925-14(2020)ASTM International (American Society for Testing and Materials), USA
MediumCurrent
Standard Practice for Sampling Liquid Paints and Related Pigmented Coatings
Focuses specifically on the practice of sampling liquid paints, similar to the sampling section of IS 101.
Key Differences
≠The Indian Standard combines sampling, sample examination, and test panel preparation into a single document. Modern international practice separates these topics into distinct standards (ISO 15528 for sampling, ISO 1513 for examination, ISO 1514 for panels).
≠ISO standards provide much more detailed specifications for sampling equipment (e.g., types of sampling tubes) and procedures for different container types, whereas IS 101 is more general in its descriptions.
≠ISO 1514 lists a wider variety of standard panel substrates (steel, aluminum, glass, wood, plastic) and references other specific ISO standards for their material properties and pre-treatment, which is more comprehensive than the IS code's list.
≠The international standards (ISO/ASTM) are regularly updated (e.g., 2020s), reflecting current technology, safety practices, and terminology. IS 101:1986 is significantly older and has not been revised to incorporate these advancements.
Key Similarities
≈All standards share the fundamental objective of ensuring a representative sample is taken and prepared in a standardized manner to yield reproducible test results.
≈Both the IS code and its international counterparts emphasize the critical need for thorough mixing of the material before taking a sub-sample for laboratory testing.
≈The requirement to clearly label sample containers with essential information such as product name, batch/lot number, date of sampling, and source is a common and mandatory procedure in all standards.
≈The underlying principle of using clean, uniformly prepared test panels as a consistent substrate for applying coatings for testing is a core similarity across all mentioned standards.
Parameter Comparison
Parameter
IS Value
International
Source
Minimum Laboratory Sample Size
Not less than 250 ml.
To be agreed between parties; typically 500 ml or 1 litre to allow for multiple tests.
ISO 15528:2020
Sampling Levels in Large Containers
From top, middle and bottom levels.
Specified levels: 10% from the surface, middle of the container, and 10% from the bottom.
ISO 15528:2020
Standard Mild Steel Panel Thickness
Approximately 1.25 mm thick (18 BG).
Typically 0.8 mm ± 0.07 mm for cold-rolled steel (references ISO 3574). Emphasis on consistency.
ISO 1514:2022
Panel Cleaning Solvent
A suitable hydrocarbon solvent (like mineral turpentine).
Specifies suitable aromatic hydrocarbons (xylene) or aliphatic/aromatic mixtures, and explicitly prohibits chlorinated solvents.
ISO 1514:2022
Time Limit for Testing
As soon as possible, but not later than seven days after receipt.
No maximum holding time specified; focuses on conditioning the sample at standard temperature (23 ± 2)°C for a defined period (e.g., 24h) before testing.
ISO 1513:2022
Sample Container Material
Clean, dry, wide-mouthed containers of glass or tinplate.
Containers made of material that will not react with the sample (e.g., glass, certain plastics, lacquered metal), with considerations for light sensitivity.
ISO 15528:2020
⚠ Verify details from original standards before use
Key Values3
Quick Reference Values
Standard viewing angle for visual comparison45 degrees to the incident light
Standard viewing distanceApproximately 500 mm
Preferred artificial illuminantCIE Standard Illuminant D65