In the mid 60's I was into stamp collecting, specializing in Japanese stamps.

I had just won a Korean auction of 4 semi-rare Japanese stamps at a cost of $380(1960 dollars).

My five year old niece watched in puzzlement as I removed each stamp from it's glasene envelope with stamp tongs, carefully inserted it into a plastic mount and licked the back of the plastic mount before affixing it to the proper space in the stamp album.

Suddenly her eyes lit up in recognition and she said: "Oh, I see, it's a sticker book!"