vintagedancer.com is a great source for the science of fabrics. Polyester hadn't been invented yet, so the basis plant, animal fibers were used, but in very, very creative ways. cotton - Levis, seersucker; rayon, wool, silk, felt, jersey, velvet, and of course, the horribly flammable flannel.

If you watch the old baseball film of the baseball greats, you'll notice there is not stretch in their uniforms because polyester hadn't been invented yet. They had no "stretch" elastics, etc, which is why they look so baggy.

Another source is if you watch old movies on TCM.com. The actresses' wardrobes are great examples of the creativity of these designers.

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edit: there was lots of rationing of cotton and wool, because the first priority was, of course, the military for uniforms, blankets, and first aid.