It was initially sold in 70 yard skeins. It was a 50% Rayon, 50% Cotton, 4-ply blend.
American Thread brought the yarn to market in 1949 at the average price (for that time period), of 25 center per skein.
In the mid 1950's the fiber blend was changed to 75% Nylon and 50% Cotton.
In 1978 another fiber change was made to the product; it is now 100% Kodel Polyster and is now referenced as a 3-ply yarn. Shortly after, skeins sizes also expanded to include 60 and 180 yards.
Over this long life-span, American Thread issued several pattern books, all termed "Star Rug Book", followed by the actual book numbers. These books largely contain rug patterns .... a rather great assortment, I must say.
And, of course, advertised in many of the needlecraft magazines.
Photo from Ebay Seller ksn3229.
Sales of this plugged along until it was discontinued on 1979. It had, indeed, a long and successful life.
Now, if you have one of the patterns and are looking for a substitute, I'd suggest that about any brand of Heavy Rug Yarn, 3 or 4 ply, that meets the stated gauge, is going to do. Or, should you be looking for a pattern, I have quite a few in the shop.
Thanks for dropping by,