whichever way you cut your strips, they can all be used....but if you cut lengthwise, you may run short of fabric.....just a quick bit if info about selvages....be sure to cut them off when subcutting your strips as the selvage is woven differently than the rest of the fabric and will shrink differently.....it could cause some funny little waves in the fabric....all selvages are different widths, so be sure to check from the backside where the difference is more distinguishable and get it all cut off.