Editing Double-shot moulding (section)

==Production==
As the name suggests, double-shot moulding is a two-step process. In the first step, the legend or graphics to be placed on the keycap, are moulded in plastic<ref>Deskthority — [http://deskthority.net/photos-videos-f8/visited-signature-plastics-for-real-t4216.html Visited Signature Plastics for real]</ref>. The plastic insert, resulting from the first step, is then placed into another mould, and plastic is inserted under heat to combine both moulds to a single piece keycap.

The technicalities of this process vary quite distinctly between manufacturers. In many cases, the process leads to a striped pattern within the keycap formed from the two different coloured plastics. This striped pattern remains even when keycaps are manufactured for engraving or other marking processes, as is clearly visible with [[Devlin Q series]] keycaps.

Other manufacturers use a wholly or near-wholly solid first shot, that gives keycaps a "nested" or "stacked" appearance when viewed from below. Regardless of the specifics, double-shot keycaps can be identified by observing the underside where both colours are visible.

[[File:Double-shot moulding.jpg|640px|centre]]

Despite the name, the moulding process is not restricted to two colours: triple and quadruple<ref>Deskthority — [https://deskthority.net/keyboards-f2/quad-shot-keycaps-t7759.html Quad-shot keycaps?]</ref> shot keycaps exist, where two or three different legend colours are present on a single keycap. The use of more than three colours is however quite rare. More commonly, where multiple legend colours are required, the additional colours are provided using pad printing (dye sublimation would be unsuitable with the ABS material used in double-shot moulding). This is especially true where the extra text is printed on the front of the keycap, such as with [[NeXT]] keyboards.

===Materials===
The majority of double-shot keycaps are made entirely from [[ABS]] plastic. Despite their greater wear resistance, [[Signature Plastics]] have confirmed that the majority of [[Comptec]] keycaps were nonetheless made from ABS, albeit of different formulations (the plastic formulations have since changed due to regulatory requirements).<ref>Correspondence with Signature Plastics, 2015-10-02</ref> Older [[Cherry catalogues]] show that in 1982, the tall [[Cherry M7]] and [[Cherry M9]] keycaps were made of double-shot Tenite, while their other double-shot keycaps were all ABS.

ABS is typically chosen because most other plastics shrink too much in the moulding process.{{citation needed}} Modern ABS however lacks the desired wear resistance, leading to keycaps that develop shine too readily. However, PBT double-shot keycaps are now produced by both [[Vortex]] and [[Tai-Hao]].