I'm sewing my blocks today. What fun! Thought I would give everyone a little hint. After sewing the 2.5 inch square to the 3.5 inch white,you don't have to trim. This will keep your block more square because of it being on the bias. I have done that for years and there is no problem when sewing the blocks together. This is a little hint I picked up on in some class. It works, try it!