book

Portable written record. Substances used to make early books included leaves, bark, linen, silk, clay, leather, and papyrus. In about AD 100–150, the codex or paged book, as opposed to the roll or scroll, began to be adopted. Vellum (parchment of calfskin, lambskin, or kidskin) was generally used for book pages by the beginning of the 4th century, and its use lasted until the 15th. It was superseded by paper, which came to Europe from China. Books became widely available only after the invention of the printing press in the 15th century (see also publishing). Printed text is also reproduced and stored in microform.

According to a report published in June 2001 by the Book Industry Study Group, US book sales continued to decline. Sales of paperbacks in 2000 decreased by 14.2% on the previous year, hardbacks by 12.9%, and general interest books by 3.3%. However, the market with the highest growth in sales was children's books, with sales rising 10.1% – largely on the wave of popularity of J K Rowling's Harry Potter books.