Checkerboard Charts / Spreading Rate Charts
One of the earliest hiding power test surfaces was linoleum with a black and
white checkerboard pattern. This was soon replaced by sealed paperboard charts
of which Forms 10H and 10H-BG Spreading Rate Charts are typical examples.
Designed for brushout tests at specified spreading rates such as in ASTM Method
D 344 and Canadian 1-GP-71, they are also used for drawdown applications like
their smaller counterparts Forms 10A and 10B. Black and gray squares in Form
10H-BG provide reduced contrast for testing coatings with lower hiding power.