There was no money in the early fur trade. and in his Fort Alexandria post journals, Alexander Caulfield Anderson often noted that he entered his trades with the natives in 'the blotter.' One imagines that the blotter might be a large piece of blotting paper lying flat on his desktop, but it is not. Quite by accident, I discovered the Fort Rupert Trade Blotter for the years 1876-1881, in the Provincial Archives of British Columbia, filed under the number A/C/20/R2.3.
The Fort Rupert Trade Blotter is a ledger, and it lists all the furs traded in on the left side of the page -- with the products the furs were exchanged for on the right side. Sometimes even the name of the native hunter is recorded. It is an amazing document, and I am not sure that many of these Trade Blotters have ever made it to the Hudson's Bay Archives. For a fur trade historian, this document reveals a wealth of information about the fur trade of the fort they were researching -- and native genealogists might enjoy finding their ancestors' trades recorded in the pages of the post's Trade Blotter.
If anyone else has run across a Trade Blotter anywhere, please let me know.