Have you found the perfect pattern, but can't find the yarn it calls for? Did you fall in love with some yarn, but don't know what you can make with it? Did you make a hat that wouldn't fit because your gauge was off? Here's your chance to learn some of the answers to those questions and more. We'll review yarn weights, fiber content, how to substitute yarns, gauge, yards vs. meters, reading yearn labels, testing dye lots, and much more.