A February 1941 article by Nellie Sargent Johnson explaining how to write key drafts, check drafts, and actual threading drafts for three-block overshot patterns on four harnesses. It works through five figures, showing how to arrange threadings for a given number of warp threads (for example 600, 240, 420 and 720), including worked arithmetic for selvages and the starting point of the repeat. It also gives rules for writing overshot selvages and for threading blocks "on opposites".