I use jelly rolls for any pattern that uses longish strips or pieces not more than 2.5" in height. I do a lot of "scrap" quilting and the rolls are a perfect size for cutting small squares or triangles which are my preference. I use the charm packs for the same scrap quilts, frequently cutting them even smaller. I love the assortment of colors you get in each jelly roll or scrap pack and they are usually sold along side yardage of the same fabrics.