If they're 1.5" wide then you will lose .5" to the seam allowance, so you will have 1" finished strips. Jelly rolls are 2.5" wide and finish at 2". You will have enough for a quilt that is ABOUT 42x40 if you have 40 strips. It will look fine, but will be a lot more work than sewing jelly rolls for the same size quilt, because your strips are only half as wide finished. Be sure to post it if you make it. Another use for your strips would be a log cabin, if you have half light and half medium to dark...