yarn weights
(Albuquerque, NM, USA)
I began knitting in 1962. Over the years, I noticed that the weights of yarn have been consistantly decreasing. Knitting worsted weight (commonly referred to in California as 4-ply yarn), is now about 75% of the thickness as it was 20 or 30 years ago. In order to achieve the same thickness as used to be obtained with a USA #8 needle, now requires a USA #6 or #7 needle.
The yarns weights can also vary according to the manufacturer of the yarn. Wool is increasingly hard to find in this country, as most of the Mom & Pop yarn shops (where just about any kind of yarn from any country could be bought)are going out of business.
Hope this helps.