1. Sew together a light print 2×42" strip and a medium or dark print 2×42" strip to make a strip set (Diagram 1). Press seam toward medium or dark print. Repeat to make 21 strip sets total. Cut strip sets into 420—2"-wide segments.
2. Referring to Diagram 2, sew together two segments to make a Four-Patch unit. Press seam in one direction. The Four-Patch unit should be 3-1⁄2" square including seam allowances. Repeat to make 210 Four-Patch units total.
3. Use a pencil to mark a diagonal line on wrong side of each light print 3-7⁄8" square.
4. Layer each marked light print square atop a medium or dark print 3-7⁄8" square. Sew each pair together with two seams, stitching 1⁄4" on each side of drawn line (Diagram 3).
5. Cut a pair apart on drawn line to make two triangle units. Press each triangle unit open, pressing seam toward medium or dark print, to make two triangle-squares (Diagram 3). Each triangle-square should be 3-1⁄2" square including seam allowances. Repeat to make 168 triangle-squares total.
6. Referring to Diagram 4, sew together five Four-Patch units and four triangle-squares in three rows. Press seams toward triangle-squares. Join rows to make a Jacob’s Ladder block; press seams away from center row. The block should be 9-1⁄2" square including seam allowances. Repeat to make 42 blocks total.