I concur with NicholasC. These were cut out from postal stationary, which can be found in a special "back of the book" section of stamp catalogs.
I am not familiar with Canadian stamps, so I used generic tools: Google or Bing. After cropping your image to just the 8¢ stamp, I went to
www.google.com (or
www.bing.com), clicked the camera/image icon (actually, an unnecessary step), and uploaded your 8¢ stamp image.

Google's 58th (approximate) result via eBid.net seemed to be a match. The webpage called it "EN89". Browsing that same auction website, I found a matching 3¢ stamp labeled "EN83".