Meaning and use
4.1 Laboratory measurements of the applied properties of architectural coatings are usually made using a blade coater, which lays a film of uniform thickness. Applicators such as brushes and rollers typically apply films that lack uniformity due to changes in rheology, film construction, flow, and leveling properties, resulting in the actual coverage of most coatings being less than measured on films applied with a scraper type applicator. This guide provides an indication of the actual application properties of coatings applied by contractors or consumers.

ASTM D7073-12 Guide to Application and Evaluation Standards for Brushing and Painting Coatings

Step 1: Scope
1.1 This guide describes the application of paint or paint coatings to brushes or rollers or both that seal wallboard to evaluate the performance of the application.

1.2 Since both application and panel evaluation are subjective, this guide should only be used for comparison testing in one lab, using one operator per application, as the ratings assigned by different LABS may not be consistent.

1.3 Values expressed in SI units shall be considered standard. The values given in parentheses are for reference only.

1.4 This standard is not intended to address all safety concerns, if any, associated with its use. It is the responsibility of users of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory restrictions prior to use.