I learned how to do partial seams after one of the blocks sewn into a pieced top was, oh, so obviously turned wrong. It had to be corrected. When I started removing the block, I just knew I had to have some space to resew it. I left about 1 ~ 1.5 inches on each corner and had no problem rotating the block and resewing it back in and it was square. Several blocks I have sewn had to have partial seams done, and even though the pattern instructions said leave only about 1/2", I left up to 2" and was a lot happier with the ease of getting everything together. I did do a backstitch when I stopped on the partial seam. That kept the seam tighter and easier to finish sewing together,