Sitka spruce was purchased from a local wood supplier (Boone Lumber) in dimensions of 4"x6"x10'. Three pieces were hand picked out of the available stock to conform to AC 43.13-1B with minimal grain slope, knots, pitch pockets, and warping. The pieces were then rough sawn on  a table saw to a larger dimension than needed, then brought to an exact dimension with a table top planer. 

Pieces were then re-evaluated for conformity to AC 43.13-1B. Sections containing knots or other deformities were marked with a pencil to be cut out, with the surrounding wood still being used (as long as it conform to the standards).