New guy here, and a bit confused. I know absolutely nothing about sewing machines, so I'm reading a lot of material (great site, by the way!) about the different sewing machines and I see a lot about 441 clones. When I finally get around to buying a machine, it will be used for anything from purses to western belts and holsters. Another question I have is about the thread sizes being used. I have seen where thicker thread is used on top and thinner thread on bottom. Doesn't this defeat the pur