Originally Posted by Holice
It depends on which OBW design you use. There appears to be some confusion on OBW designs. Do you plan on doing the one using triangles or 4 pieces.
You have to compute based on your planned pattern and the number of repeats you have in the fabric.
OBW uses either 6 or 8 repeats, always triangles that form hexagons or octagons. 4-patch posie uses 4 repeats (squares) and stack and whack uses various repeats, usually triangles I think.