There are two types of sticker paper backing. The American and the Japan sticker sheets have a lightweight, thin, and fragile type of paper. The U.K., German, and Taiwan sticker sheets are thicker, heavier, and more durable.
Location of serial numbers on standard sticker sheets:
AMERICA: top right. (But I also have a variation in which the serial number is in the middle right square. See here.)
JAPAN: top right.
U.K., GERMAN, and TAIWAN: bottom left.
CANADA: bottom right.