This page is a work in progress, to be updated as I learn about various supplies out and about the city of Montreal:
Craft/Art Supply Stores
Omer de Serres
British Blue Print & Co : art supplies, cluttered but good for block printing inks
Resin: Not a traditional venue, but ask for clear resin and they've got it!
B&B school supplies (origami paper)
Japanese Washi Paper : http://www.aupapierjaponais.com (they also have interesting paper based craft courses)
Origami Montreal Club (en francais)