I received a recent inquiry regarding the use of "points" on blankets and whether they related to weight or thickness of the blanket. I thought the reply might be of use to you:
Blankets, from the reading I've done on English manufacture, were indeed produced by weight (and sometimes, consequently, length of the complete piece, many many yards) as the completed blanket fabric was taken to the guild hall for weighing and approval. Various widths of fabric were produced which pertained to the ultimate size of the blankets to be manufactured.
However, the weight referred to does not refer to the individual blanket, rather the total piece which would be later cut up into pairs. The thickness of the knap and the quality of the fabric were more a function of the maker and were not indicated, as far as I have been able to determine, by the points (weight could vary from country to country, by manufacturer or weaver; the guild was the ultimate arbiter of whether the fabric was of good quality). The use of points, when they were used and not everyone used actual points apparently, were for indicating size. They would be especially useful as a handy tool for finding the right blanket at a glance.
The "point" is sort of a matter of contention. According to the HBC blanket historian, Harold Tichenor, the "point" may have evolved from French useage in the 16th century. However, there was never a consistent standard for a "point", per Tichenor, until the 19th century when HBC set a standard. In reading about blanket manufacture in Witney and Oxfordshire, there seems to have been an understood set of sizes, though they may have varied from guild hall and manufacturer (remember all work was piece work sent out to individuals and groups by the blanket company). From the use of the "point" in inventories, etc. there must have been a common understanding as to the sizes, or relative sizes each appellation indicated ( 2 point, 2 1/2 point, etc).
And yet, when the point sizes are compared by manufacturer they vary. This site (I may have already passed this on to you) has a messed up page, but toward the bottom there is a comparison of sizes to various companies late 18th into the 19th centuries: http://hrd7.tripod.com/hbc/hbc.html
Off to Grand Portage next week.