Seeking hex tiles, blank on at least one side

I'm looking for some hex tiles to prototype a game idea that I dreamed up (literally (by which I mean "really", not "metaphorically" or "emphatically")).  About the size of Catan tiles; a couple of people have suggested that I get hold of some used Catan tiles and draw on their backs.  Blank tiles are available for purchase on-line but the shipping cost is high compared to the value of the tiles.  Can anyone suggest where around Ottawa I might find such a thing?  I've tried the Comic Book Shoppe and Fandom II, and Kijiji and E-bay, without success.

(Cardboard is probably the best material for my purposes.  I'd be willing to use ceramic or linoleum or other flooring material, but such tiles are out of fashion — I've asked at a couple of flooring stores.)