If your question is: you have 4" blocks to use up and want to make a twister quilt, will the 3 1/2" twister ruler work? You may be short as the ruler is for 5" blocks. You could copy the ruler at a reduction of 80%, use the paper template to make an acrylic, plexiglas, or thick plastic (think flexible plastic kitchen cutting boards) template. Copy the lines onto the template from the paper copy. You now have a twister ruler for your 4" blocks.