Form 24B is a white, light gray and black gray scale chart. The chart is with six stripes on white field.

The stripes on this chart are numbered 1 to 6, representing uniform steps of increasing contrast. The hiding power of the applied coating is rated as the number of the darkest stripe that is completely (or almost completely) obscured, at a specified thickness or spreading rate. Paint is usually applied to this chart using a drawdown blade rather than brush or roller.