I was looking at the Pattern & Template section, and it seems that if one wants to make projects right the first time, you purchase the pattern which gives the dimensions. Thus you cut your leather to the correct size and put it together. For talking purposes, lets assume we're going to make a leather vest. Well, leather craftsman come in all sizes. Last time I tried on a sport coat, I was a size 50 "portly". I would guess that vest patterns come in S,M,L, & XL. So my question then is, do any of you sew up a muslin mock-up of the pattern and adjust it as needed before cutting into an expensive piece of leather? It seems that in dress making, they do make some type of cheap mock-up before cutting expensive material. So it would seem the same for leather work. If so, then do you use muslin, felt, or some other material readily available at your local fabric store?