The Stain Glass Window items were designed over a few years and added to ravelry as they became available. Now that all 3 are finished an eBook was the next logical step. They are all made with Worsted Weight Yarns, Any fiber content will work. I like a solid with a variegated yarn as the stain glass window part. But you can use individual colors on each row as you go up. They are made using only one yarn at a time which makes it an easy knit. The second yarn is carried behind the work which also adds a little more thickness for a warmer piece.