This is a precise instrumental method giving results having an absolute physical significance without reference to a comparison paint. It should be used when maximum precision and minimum subjectivity are required, as in testing specification coatings or evaluating the hiding efficiency of pigments.

Hiding power Test Method D344 is visual instead of instrumental, and gives results that are relative to a material standard instead of absolute. It is less precise than Test Method D2805 but more closely aligned with practical painting procedures.

1.1 This test method covers the determination, without reference to a material paint standard, of the hiding power of air dry coatings with Y tristimulus values greater than 15 %. With appropriate modification, it can also be used to test baking finishes.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

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.