These are sealed paint test charts with six stripes on a white field, ranging in shade from very light grey to black. The stripes are numbered 1 to 6, representing uniform steps of increasing contrast. The hiding power of the applied coatings is rated as the number of the darkest stripe that is completely (or almost completely) obscured, at a specified thickness or spreading rate. Form CU-1 is used for more practical large-area brush or roller applications as in ASTM D 5150. Applications on Form 24B are with a drawdown blade.