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.
| 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 |