1977 Canada, set of 16.
Canadian ADPAC stickers. These are very similar to the U.S. stickers, also originally found in boxes of cereal. There are 16 total stickers in this set, and the colors vary after each 4. The green and red stickers are fairly common; the yellow and purple are more rare. I've heard rumors that the purple and yellow stickers never actually made it into cereal boxes, although they were printed. Several of the sheets hit the aftermarket after the promotion was over, and have been sheet cut and distributed to collectors.
WANTS FROM THIS SET: The two yellow stickers not pictured.
