section_path: Contemporary publishing/Manufacturing
section_name: Manufacturing
paragraph_text: Manufacturing
  
  The methods used for the printing and binding of books continued fundamentally unchanged from the 15th century into the early 20th century. While there was more mechanization, a book printer in 1900 still used movable metal type assembled into words, lines, and pages to create copies. Modern paper books are printed on paper designed specifically for printing. Traditionally, book papers are off-white or low-white papers (easier to read), are opaque to minimize the show-through of text from one side of the page to the other and are (usually) made to tighter caliper or thickness specifications, particularly for case-bound books. Different paper qualities are used depending on the type of book: Machine finished coated papers, woodfree uncoated papers, coated fine papers and special fine papers are common paper grades.
  
  Today, the majority of books are printed by offset lithography. When a book is printed, the pages are laid out on the plate so that after the printed sheet is folded the pages will be in the correct sequence. Books tend to be manufactured nowadays in a few standard sizes. The sizes of books are usually specified as "trim size": the size of the page after the sheet has been folded and trimmed. The standard sizes result from sheet sizes (therefore machine sizes) which became popular 200 or 300 years ago, and have come to dominate the industry. British conventions in this regard prevail throughout the English-speaking world, except for the US. The European book manufacturing industry works to a completely different set of standards.
  
  Hardcover books have a stiff binding, while paperback books have cheaper, flexible covers which tend to be less durable. Publishers may produce low-cost pre-publication copies known as galleys or "bound proofs" for promotional purposes, such as generating reviews in advance of publication. Galleys are usually made as cheaply as possible, since they are not intended for sale.