A sticker album is a book where a person collects stickers to stick in the book on designated sections. Sticker album themes can be based around sporting events such as the FIFA World Cup or TV shows like Doctor Who.The stickers are usually sold in blind packs, so the purchaser does not know which stickers they are buying. This can mean a collector has to buy huge numbers of packs to complete their collection. Collectors get around this problem by swapping or selling their spares with other collectors. Panini, the largest producer of sticker books insist that they produce equal numbers of all the stickers in every collection.