Have you ever really looked at the garment care instructions label sewn into your clothes? Even the simplest underwear will have a tiny polemic attached to the waistband: Machine wash warm with like colors. Only non-chlorine bleach when needed. Tumble dry low, iron if desired. So why do you never get a label that reads: Hand wash in boiling water with colors that bleed. Apply chlorine bleach and scissors when needed. Air dry in a crumpled wad. I got to thinking about the origin of these labels, and I was surprised that it was darn easy to learn all about them! There's lots of great info here at the Vintage Fashion Guild website, which posts a guide to dating vintage clothing. I've never been much into vintage clothes, but it's very neat that you can identify World War II-era shoes by the fact that they were commonly made of exotic leathers such as crocodile. Anyway, garment care labels were introduced in the United States in 1971. Before then, people just had to decide for themselves how to wash their underwear. I have to admit, I've ignored the "Dry Clean Only" admonition more times than I can count, with very few ill effects. Yes, silk is hand washable. So is wool. Crocodile boots, not so much.