Patch, And Ball Size Suggestions?

A grain is a unit of measurement of mass, and in the troy weight, avoirdupois, and Apothecaries' system, equal to exactly 64.79891 milligrams. It is nominally based upon the mass of a single virtual ideal seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat and barley grains were part of the legal definitions of units of mass. Rather, expressions such as "thirty-two grains of wheat, taken from the middle of the ear" appear to have been ritualistic formulas, essentially the premodern equivalent of legal boilerplate.[1]:27[2] Another source states that it was defined as the weight needed for 252.458 units to balance a cubic inch of distilled water at 30 inches of mercury pressure and 62 degrees Fahrenheit for both the air and water.[3] Another book states that Captain Henry Kater, of the British Standards Commission, arrived at this value experimentally.[4]

The grain was the legal foundation of traditional English weight systems,[5] and is the only unit that is equal throughout the troy, avoirdupois, and apothecaries' systems of mass.[6]:C-6 The unit was based on the weight of a single grain of barley, considered equivalent to 1 1⁄3 grains of wheat.[5][7]:95 The fundamental unit of the pre-1527 English weight system known as Tower weights, was a different sort of grain known as the "wheat grain".[8] The Tower wheat grain was defined as exactly 45⁄64 of a troy grain.[1]:74​