Foolscap is a traditional paper size used in Europe and the British Commonwealth before the adoption of the international standard A4 paper. It is paper cut to the size of 8+1⁄2 × 13+1⁄2 inches (216 × 343 mm), sometimes 13 × 8 in (330 × 200 mm) . The name "foolscap" comes from the watermark of a fools cap that was commonly used on paper of these dimensions in the 15th century onwards. Foolscap was popular with Regency letter writers because it had a generous surface upon which much could be written before the sheet was folded down to be addressed and sealed. Today, foolscap is mainly used in North America as lined, legal-size paper, while in some South American countries, it is called "oficio" because it is or was used for official documents. The difference between foolscap and A4 paper is that foolscap is slightly larger, measuring 8.5 inches by 13.5 inches, which makes it a practical folder or clipboard, allowing extra room for an A4 piece of paper to fit in, and this prevents the corners from folding or important essays or documents from becoming squashed.