Other variations of football products exist, such as marbles, cut-outs, coins, stamps and stickers, some made of light cardboard and attached with glue or stickers, into sticker albums specifically issued for the products. Forming a partnership with FIFA in 1970, Panini first produced a World Cup sticker album for the 1970 World Cup. Initiating a craze for collecting and trading stickers, since then, it has become part of the World Cup experience, especially for the younger generation. "The Guardian" states, “the tradition of swapping duplicate Cup stickers was a playground fixture during the 1970s and 1980s.” Panini begins assembling World Cup squads for their sticker album a few months before they are officially announced by each nation, which means surprise call ups often don’t feature in their album. A notable example of this was 17-year-old Brazilian striker Ronaldo who was called up for the Brazil squad for the 1994 FIFA World Cup.