Despite its worldly name, The International Bank of Canada was a very small bank only located in Toronto. It opened in 1858 and failed in October of 1859. All bank notes from 1858 issued by The International Bank of Canada should be dated as September 15th, 1858. One, two, and five dollar bills were printed. Remainders and proofs also exist. The seven varieties are based on where the note has one or two signatures, and whether it has an overprint or not. Varieties are broken down further based on the color of the overprint. Bank Notes from 1859 were printed by The American Bank Note Company for use by The International Bank of Canada and are dated as June 1st 1859. Only ten, twenty, and fifty dollar bills were printed. Twenty dollar bills are scarce. The two other denominations are relatively common.
(Info from canadacurrency.com)