A big difference in advertising now and in the past is that 60 years ago consumers seemed to have a much greater knowledge about fabrics and fibers. Today it would be really strange to see an ad for a fabric, but up through the 1970s these ads were commonly found in fashion magazines. I’m betting that most people these days don’t even know what worsted is.
If you need to brush up on your fabric and fiber terminology, you are in luck. As I announced earlier, the Vintage Fashion Guild now has a Fabric Resource, and you can learn quite a bit by just reading through it. For example, worsted happens to be “Fabric made from high-twist, worsted yarns that have long, smooth fibers.” And don’t forget to click on the fabric samples to see the enlarged fabric.