I received a swatch for some inexpensive 100% wool tartan material in Black Stewart tartan. The swatch is very soft--almost like lambswool. I measured the set, and I believe it's about 3 1/4", and fairly square, if my guess is correct. My question is, how much does a yard weigh, approximately? Is this 13 oz material? If it's not, how much material would I need to make a different garment, such as a waistcoat? I'm what you'd call a medium-build person, slightly shorter than average.