Like others here, I too make my own patterns for bags. When I see one I like, such as those by James Rogers, I save the photo to my files, and make my own patterns out of Corn Flakes box card stock, which I save. You'll end up with a collection of your own patterns in short order. The patterns are useful so you can lay out all of the pieces ALL OF THE PIECES on your leather to be sure you have enough leather and that the pieces don't have flawed leather that will detract from the strength or visual quality of the finished bag. I have TC Albert's book too, and found it a useful reference book, though I have never used any of his patterns.