The Practical Hiding Power Paint Chart, Form CU-1M, is a sealed test chart with a series of stripes ranging from light to dark gray and black. The reflectance values of the gray shades are selected with the objective that their color differences (vs the white surround) will be in the geometric sequence: 2, 4, 8, 16, 32, and 64 CIELAB units.
The test area consists of the entire chart less the narrow gray borders with numbers. Full details with regard to reflectances and tolerances are tabulated in ASTM D5150.
Practical application tools for architectural coatings, such as paint rollers and brushes, typically apply films that vary in thickness due to incomplete leveling. Thus the effective one coat hiding power of most architectural paints is considerably less than that determined by customary laboratory procedures, which generally call for uniform films applied with a blade applicator.
|Test Area||Overall Size||Thickness|
|6 sq. ft.||24" x 37.25"||11.5 mils|
|5574 cm2||610 x 946 mm||0.3 mm|
The procedure described in ASTM Method D5150 is somewhat different than the above, having been designed specifically for roller application tests performed in a specialized manner.