I use my 12.5" square ruler often to square up blocks, cut multiple strips; although last year I purchased a Fiskar's rotary cutter and ruler that I love when cutting strips, squares, etc. and it doesn't aggravate my carpal tunnel. I also frequently use my 6", 6.5 and 4.5 rulers when squaring up portions of blocks/blocks. I try hard to keep my 1/4" seams, but I am sometimes off by a little bit; and I like to square up smaller portions of a quilt block as well as the quilt block; even if I just trim a smidgeon, my blocks come out better and so does my quilt.