A three-page instructional article from February 1940 by Nellie Sargent Johnson on designing crackle weave threadings for four harnesses. It explains the weave's Scandinavian (Jamtlandsvav) origins, the four overlapping pattern blocks (1&2, 2&3, 3&4, 1&4) built from three- and four-thread units, and how to draw down and key-draft them. It also covers building twill, herringbone and rose-path orders, repeating unit blocks, and the tie-up, including the Structo loom, with threading drafts, drawdowns and key drafts.