1 n. — originally Fur trade
a type of woollen blanket sold by the Hudson's Bay Company (see Image 1).
Type: 1. Origin — The Hudson's Bay blanket, known in full as the Hudson's Bay Company point blanket, was introduced to the fur trade in 1780 (see HBC Heritage reference). A blanket's "points", according to a system originally developed in France in the 1700s, were indigo lines woven into the sides to indicate the overall size of the finished product. One point typically measured four to five inches and the "standard measurements for a pair of 1 point blankets was: 2 ft. 8 in. wide by 8 ft. in length; with a weight of 3 lb. 1 oz. each" (see HBC Heritage reference, "The Point System").
Trade value varied from post to post and also depended on the quality of the actual blanket in conjunction with its size, but one "made beaver" (a whole pelt in good condition) was often enough for a 1-point blanket (see Parks Canada reference). The Hudson's Bay blankets came in several colours. They were were popular with Aboriginal peoples as trade goods as the durable fabric was used for making clothing, especially coats (see also blanket coat). The white ones were popular for making coats for winter hunting in the snow.
The striped style that the company is most famous for, a white background with bars of indigo, yellow, red and green (see the bottom of Image 1), was first introduced in 1800 (see HBC Heritage reference). At present, this "multistripe" version of the Hudson's Bay blanket is sold at HBC stores across Canada, along with a host of similar fashion and home decor products. The term is most frequent in Canada (see Chart 1).
See also COD-2, s.v. "Hudson's Bay blanket", which is marked "Cdn".
See also: beaver (def. 4) blanket coat Hudson's Bay (def. 3) point blanket
- 1870  [Pambrun pays Indians what he thinks right: Paluce chief, for horses and services, one three-point Hudson's Bay blanket, one check shirt, one knife, half a brace (three feet) trail-rope tobacco. Gray thought the price paid was very reasonable, -- quite little enough for the labor, to say nothing of the risk and suffering from cold on the trip.] 
- 1898  His knowledge of the work required, and his confidence in my ability to do this work, more than made up to me at the time for the fact that there was not a dollar of appropriation from the Missionary Society. But father gave us a pair of four-point Hudson's Bay blankets, two hundred ball and powder, and some net twine, together with his confidence and blessing; to which in all things mother said, "Amen." 
- 1921  It is my experience that there is no easier way to get rid of a bad cold than to sleep out in the snow, wrapped in a Hudson's Bay blanket, a caribou robe, or a rabbit-skin quilt, when the thermometer is about fifty below zero.
- 1934  Let us have long woollen breeches in some vivid hue, fitting snugly at the ankle and waistline, which will be smart for skating and skiing -- and let us have a shirt of that striped Hudson's Bay blanket with a shining zipper skimming up to the chin in front -- to keep out the wintry blasts and, of course, waylay the seiges of vanity.
- 1963  I recall a motel in Manitoba that insisted we bring our muddy dogs indoors where they slept on scarlet Hudson's Bay blankets at the foot of the beds.
- 1989  One by one, the arcades, Greek pizzerias and ice cream vendors begin the process of shuttering up for another winter, and the smell of cottage mothballs can be imagined along main drag.
Things are a bit different this year.
Huddled together under Hudson Bay blankets between takes, dozens of harried souls are struggling to simulate heart-of-summer hijinx for celluloid glory. Over two years in development, Sylvan Lake Summer has finally come into production. 
- 1999  The year is 1928. The place, Amsterdam. For the first time, women are competing in selected track and field events in the Olympics. On the last day of the meet - and it's a cold and damp day - a 20-year- old from Saskatoon is wrapped in a Hudson Bay blanket while waiting her turn in high jump.
Ethel Catherwood, known as the Saskatoon Lily, clears five feet, 2 9/16 inches. 
- 2008  Other chapters examine the history of draft evasion in various parts of the world, including Canada. One noteworthy anecdote pertains to the Second World War when some resisters hid in caves in rural Quebec. The women hung Hudson's Bay blankets on clotheslines to warn the men when the police were nearby.
Throughout the book, Frutkin reflects on the benefits of solitude in the manner of a latter-day Thoreau. 
- 2014  Most heinously of all, Charles was handed a big pile of gifts to cart home to the United Kingdom, where the Royal Family must operate entire warehouses to store all the junk they're given during their many visits to the nations once ruled by colonial Britain. "Great, more crap," Prince Charles ought to think to himself every time somebody foists a new Hudson's Bay blanket or cowboy hat into his royal lap. 
2 n. — historical
paper currency issued by the Hudson's Bay Company.
Type: 3. Semantic Change — Notes of various denominations were first issued by the Hudson's Bay Company after the establishment of the Red River Settlement in 1812, as the need for a form of currency arose among the colonists (Gingras 1968: 40). The notes were issued in the amounts of one shilling, five shillings, one pound, five pounds and ten pounds. Because the company's thick woollen blankets were a major trading commodity at the time, the term Hudson's Bay blankets was adopted as a nickname for the bills as well. As stated by Gingras (1968: 40), HBC halted circulation of the notes after 1870, when "the Company relinquished its territories to the Dominion of Canada".
See also: Hudson's Bay bill
- 1896  I handled, in making my purchases, the first "Hudson's Bay blankets" I had ever seen. These were large 5s. and £5 notes, issued by the Company. . . .
- 1897  The company had its own paper currency after 1825 -- "Hudson's Bay blankets" the notes were called.
- 1923  The currency of the time [c1821] consisted largely of "Hudson's Bay blankets," which were notes for one pound, five shillings, and one shilling each.
- 1955  He also saw "Hudson's Bay blankets" for the first time. These were large five-shilling and five-pound notes issued by the Company.
- 1963  The York factory, of the Hudson's Bay Co. also issued paper currency in the denominations of one Shilling, five Shilling and 1 Pound Notes. [These] [...] four and three quarters inches by nine and three eighths inches [...] known as "Hudson's Bay Blankets," were used extensively throughout Western Canada.
Images:
Image 1: Hudson's Bay blankets on display. Source: Wikimedia Commons. Photo: Decumanus
Chart 1: Internet Domain Search, 7 Aug. 2014