(Length + Width) / 2
Add the maximum height and width (in inches) of the finished patch
and divide by 2. For round patches the diameter is the size. For
all patches, round fractional sizes up to the next half inch.
Embroidery coverage defines the amount of embroidery
across the entire surface of a patch.
We base our embroidery percentages upon 3 basic amounts:
50%, 75%, and 100%.
Gray areas represent stitching, white areas represent twill.