From a 1942 Spiegel catalog:
Text of that Important Notice About Nylon Hose:
Due to the tremendous volume of sales, our original stock of the Nylon hosiery listed on page 104 of our big Fall and Winter Spiegel catalog is now completely sold out. We will be unable to get any more for our customers for the duration because all Nylon has been taken over by the government for military purposes. However, we are sure you can fill all your hosiery needs satisfactorily from our large selection of silks, rayons and lisles.
In fact, the War Production Board commandeered silk first, then nylon, but silk, being pricier the $2.98 you’d spend for three pair of silks in 1942 equals about $39 today didn’t disappear as quickly from stores and catalogs.
(Via Found in Mom’s Basement.)