Test Panel Preparation, Film Thickness & Conditioning
Every IS 101 paint-film test depends on a correctly prepared substrate: a standard, cleaned test panel, the paint applied at the specified film thickness and number of coats, dried and conditioned at standard temperature and humidity for the specified period before testing. Panel preparation and conditioning are the controlled variables that make hardness, drying-time and adhesion results comparable across labs and batches.
Key Requirements
•Use the specified standard test panel, cleaned/prepared per IS 101 Part 1 (substrate affects film behaviour)
•Apply the paint at the specified film thickness, number of coats and method (brush/spray/applicator)
•Dry and condition the film at standard temperature/humidity for the specified period before testing
•Test only after the film has reached the required dry/cure state for that method
•Report panel type, film thickness, drying/conditioning regime alongside the result
Practical Notes
✓Hardness and drying-time results are only comparable at the same film thickness and conditioning regime — always report the regime with the result.
✓Substrate and film thickness change measured hardness as much as the paint formulation does — control them, don't let them be the unrecorded variable.
Common Mistakes
⚠Testing at uncontrolled temperature/humidity, then comparing results between labs or batches.
⚠Variable/unrecorded film thickness, which alone shifts hardness and drying-time results.