Paper size a number of different sizes were defined for large sheets of paper, and paper sizes were defined by the sheet name and the number of times it had been folded. Thus a full sheet of "royal" paper was 25 × 20 inches, and "royal octavo" was this size folded three times, so as to make eight sheets, and was thus 10 × inches. Imperial sizes were used in the United Kingdom and its territories. These sizes are no longer commonly used since the UK switched to ISO sizes. Many of these sizes were only used for making books (see bookbinding),
Sheet pan side flat, so that it is easy to slide the baked product off the end, may be called a cookie sheet. Professional sheet pans used in commercial kitchens typically are made of aluminum, with a raised lip around the edge, and in the United States come in standard sizes. European pan dimensions are governed by GN numbers under European Committee for Standardisation EN 631. In American sizing, the full-size sheet pan is , which is too large for most home ovens. A two thirds sheet pan (also referred to as a three quarter size sheet pan) is . A half