4.1 Free films are required for conducting tests to evaluate physical and mechanical properties such as tensile and elongation (Test Methods D2370 and E96/E96M), moisture vapor permeability (Test Methods D1653), and other physical properties of organic coatings where the substrate may interfere with the determination.

1.1 This practice covers the preparation of free films of organic coatings for use in determining the physical properties of the coatings. Procedures are given for preparing free films on three alternative substrates. These substrates are treated FEP (fluorinated ethylene-propylene) sheet, silicone coated paper, and halosilane coated glass plates.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.