   thumb|right|220px|calender process thumb|right|220px|old calender machine thumb|right|220px|calender machine using bales of rubber thumb|calender machine for electrode pressing in lithium-ion battery manufacturing a calender is a series of hard pressure rollers used to form or smooth a sheet of material such as paper or plastic film. in a principal paper application, the calender is located at the end of a papermaking process (on-line). those that are used separate from the process (off-line) are also called supercalenders. the purpose of a calender is to make the paper smooth and glossy for printing and writing. ==calender section of a paper machine== the calender section of a paper machine consists of a calender and other equipment. the paper web is run between in order to further smooth it out, which also gives it a more uniform thickness. the pressure applied to the web by the rollers determines the finish of the paper, and there are three types of finish that the paper can have. the first is machine finish, and can range from a rough antique look to a smooth high quality finish. the second is called a supercalendered finish and is a higher degree for fine-screened halftone printing. the third type of finish is called a plater finish, and whereas the first two types of finish are accomplished by the calender stack itself, a plater finish is obtained by placing cut sheets of paper between zinc or copper plates that are stacked together, then put under pressure and heating. a special finish such as a linen finish would be achieved by placing a piece of linen between the plate and the sheet of paper, or else an embossed steel roll might be used. after calendering, the web has a moisture content of about 6% (depending on the furnish). it is wound onto a roll called a tambour, and stored for final cutting and shipping. ==etymology== the word "calender" itself is a derivation of the word ÎºÏÎ»Î¹Î½Î´ÏÎ¿Ï kylindros, the greek word that is also the source of the word "cylinder".merriam-webster definition ==history== in 1836 edwin m. chaffee, of the roxbury india rubber company, patented a four-roll calender to make rubber sheet. chaffee worked with charles goodyear with the intention to "produce a sheet of rubber laminated to a fabric base".{{cite book|last1=simpson|fir
Manufacturing Papermaking