Assemble B Blocks
1. Sew black print No. 2— 2-5/8x4-3/4" rectangles to opposite edges of a butterfly print 4-3/4" square (Diagram 4). Add black print No. 2—2-5/8x9" rectangles to remaining edges of butterfly print square to make a block B center. Press all seams toward black print No. 2 rectangles. The block B center should be 9" square including seam allowances. Repeat to make four block B centers total.
2. Referring to Diagram 5, sew blue print triangles to opposite edges of a block B center. Press seams toward blue print triangles. Add blue print triangles to remaining edges of center to make a Square-in-a-Square unit; press seams toward blue print triangles. The Square-in-a-Square unit should be 12-1/2" square including seam allowances. Repeat to make four Square-in-a-Square units total.
3. Use a pencil to mark a diagonal line on wrong side of each remaining assorted swirl print 3-1/2" square.
4. Align a marked swirl print square with one corner of a Square-in-a-Square unit (Diagram 6; note direction of marked line). Stitch on drawn line and trim seam allowance to 1/4". Press open attached triangle, pressing seam toward swirl print. In the same manner, add marked swirl print squares to remaining corners to make block B. Block B should be 12-1/2" square including seam allowances. Repeat to make four B blocks total.