I buy old quilts that are damaged or no longer wanted. Often a large quilt is big enough to make two coats. I designed my own pattern, making it an oversized raglan with a hood to wear over other layers. I always put large pockets on the outside and a full separating zipper. All of the seams are completely covered either using a french seam technique or with binding. Often I have to create more binding using the back side of the quilt because there isn't enough binding around the edges for a coat. I'm confident in the durability of my coats enough to recommend machine washing and drying.
