A keycap is a small plastic cover placed over the keyswitch of a computer keyboard. Keycaps are often illustrated to indicate the :Category:Computer keys|key function or alphanumeric character they correspond to. Early keyboards were manufactured with the keyswitch and keycap integrated in one unit; separate keycaps were introduced to facilitate the production of different keyboard layouts.
History
Typical keycaps the 1970s and 1980s were produced using two-shot molding, with the markings molded into each keycap in a different color of plastic. This eventually fell out of favor, as it was more expensive, and tended to produce keycaps more durable than the equipment on which they were mounted. Modern keycaps are usually labelled by stamping or laser engraving. However, two-shot molding keycaps are still available today, known for their feel and general durability.
Modern Keycaps
Keycaps can be bought in replacement sets for a keyboard. Notably, replacement sets are frequently sold for keyboards that use Cherry MX-style stems. Custom sets are bought and sold within the enthusiast communities, and artisan keycaps can be purchased individually. Keycaps are sold in printed and unprinted varieties. The unprinted variety, known as "Blank Keycaps," are said to promote touch typing and help buildmuscle memory because the user is forced to rely on motion rather than visuals. However, within the modern mechanical keyboard community, unprinted caps are typically chosen for their visual appeal. The most common plastics used are ABS and PBT. ABS is cheap but is more prone to damage and deformation by chemicals and cleaning agents. PBT lastslonger and is more tolerant to chemicals and cleaning agents, but it costs more and has a different feel that some do not like. Polyoxymethylene or POM, is also used as a keycap material. This is generally the most expensive and rarest material used to form keycaps, it is wear-resistant, solvent-resistant, and low-friction. The top of most keycaps may be described as cylinder-shaped, flat or spherical. The modern preference is for cylinder-shaped keycaps rather than spherical ones, but laptop keys are often flat. Printing of numbers, letters, and symbols on the keycaps are done using pad printing, laser etching, or dye sublimation. Pad printing is the cheapest and most common. Dye sublimination is more expensive and only done by a few companies such as Topre, ZF Electronics, and Unicomp.
