When I saw the Pinwheel Purse in Iris Schrier's Modular Knitting, I knew I had to make it. I chose to use some hand - spun silk yarn which is made from saris. With the heavier yarn, I used larger needles and my bag came out larger. This pattern is fabulous for using singles with an over twist. You don't have any biasing problems. I'm not one to go out with my wallet and keys unzipped, so I added a lining with a zipper. It consists of 3 layers: one for the back, one for the front and one with a zipper. I also added some crochet rows to the front flap to give more overlap. I carry this bag all the time and get many comments on it. If you purchase this book, you should find Art yarns address and get the list of book updates. It might save you some grief. Sorry Iris, but the old Math teacher in me has to say it. This bag is a pentagon, not an octagon, and an equilateral triangle has to have all three sides equal. That being said I LOVE this bag!!!