1. For a set of 12 matching triangle-squares (enough for one block), gather three matching bright batik 4" squares and three matching blue batik 4" squares.
2. Use a pencil to mark two diagonal lines in an X on wrong side of each bright batik 4" square.
3. Layer a marked bright batik square atop a blue batik 4" square (Diagram 1). Sew together around all edges using a scant 1⁄4" seam allowance. Cut apart on drawn lines to make four triangle units. Press each triangle unit open, pressing seam toward darker batik, to make four triangle-squares. Each triangle-square should be 2-1⁄2" square including seam allowances. (Handle edges carefully as they will be on the bias.) Repeat to make 12 matching triangle-squares total.
4. Repeat steps 1–3 to make 11 total sets of 12 matching triangle-squares each.
5. For a set of six matching triangle-squares (enough for a half block), gather two matching bright batik 4" squares and two matching blue batik 4" squares. Repeat steps 2 and 3 to make six matching triangle-squares (set aside the two left over). Repeat to make a second set of six matching triangle-squares.