I don't think I would be happy with just 6 sizes. Right now I am making these Bible bags using my Omnigrid 3.5" square up which I have seldom have used before. Lot of BQs and Warm Wishes I use the 8.5" Omnigrip square to cut my focus fabrics. I also use my Omnigrip 5.5" & 6.5" square up. I too have the 2.5"x12.5", 4"x14", 6"x14" Omnigrip. When I do cut from folded fabric, that is the only time I pull out the 6.5"x24 Omnigrid. Trimming down the Bible Bags, I am also using my 15" Omnigrid square. I don't have any trouble with the yellow lines.