This ruler will make 2" to 12" finished Kaleidoscope Blocks. All seam allowances are included when cutting all of the triangles that are used to make the Kaleidoscope Blocks, even the ability to make Half Blocks. Best of all - the Blocks are made in about half the time due to Virginia's unique "pre-sewing before cutting" technique. This is a ruler that kids can use. A pattern and complete cutting graphics are included in the packaging.