Size		Coverage %
6 x 6		12.50%
6 x 12		37.50%
12 x 12		50%
6.5 x 6.5		12.50%
6.5 x 13		37.50%
13 x 13		50%
8 x 8		12.50%
8 x 16		37.50%
16 x 16		50%