I agree with One More Quilt, a charm square is supposed to have only one square of each block; but the postage stamp quilt is supposedly 1 1/2" squares that finish to 1". Years ago, a woman in my guild made the postage stamp block quilt, BUT she strip pieced "X" number of fabrics, then cut apart into 1 1/2" wide strips x the numer of strips. It would certainly make it faster, and perhaps a little easier than handling 1 1/2" squares. It would be for me anyway, I have enough trouble seeing 1 1/2" squares, let alone sewing them. lol I'm sure your quilt will be gorgeous when it's done.