Editing Keycap printing (section)

==Laser marking==
Laser marking is the use of a laser beam to mark the legends onto the keycaps. Laser marking works well with straight lines, but has difficulty achieving clean coverage of solid fill areas such as arrowheads. There are numerous ways to alter the colour of plastic using a laser beam, and the terminology varies between manufacturers. In particular, the terms "etching" and "engraving" appear to be interchangeable in terms of which operation they refer to.

Prominent users of laser marking include [[Apple]], [[Cherry]] and [[Matias Corporation|Matias]]. The exact processes used by these companies is never described, so some guesswork applies as to which processes are used for the various keyboards and keycap sets on the market.

===Charring===
Charring, or etching, uses a laser to heat the plastic to the point that it chars to a darker shade. Traditional charred keycaps have pale grey or dark beige legends as a result of the natural colour of the charred plastic. Darker shades may instead be the result of UV-induced photo reduction, or "cold marking", which does not noticeably heat the plastic.

<gallery widths=250 heights=187>
File:Laser engraved white keycaps.jpg          | Charred keycaps on a [[Matias Tactile Pro 3|Tactile Pro 3]]
File:Monterey K110 -- laser-etched legends.jpg | Monterey K110 keycaps; solid areas are achieved using nested lines
File:Laser etching vs double-shot (detail).jpg | Double-shot vs laser-etched keycaps, depicting the reduced lettering contrast of traditional charring
File:SIIGKB1937_lasered.jpg|SIIG KB1937 laser etched legend
</gallery>

===Foaming===
Foaming as a technique is not new, although it is comparatively new to the keyboard industry. Foaming uses a laser beam to create a surface of small, hard bubbles that have a bright appearance, allowing for near-white legends on black plastic. The bubbles have a rough surface that traps dirt, and thereby stains readily. Matias use this technique with the [[Matias Tactile Pro|Quiet Pro]], and both [[WASD]] and [[QWERkeys]] offer white-on-black foamed keycaps.

<gallery widths=250 heights=187>
File:Matias Tactile Pro PC -- keycap laser foaming.jpg | Laser foamed legend on a Matias Tactile Pro PC
</gallery>

===Colouring===
Colouring uses the laser beam to burn away one of the plastic colourants, leaving other colourants behind. This allows for limited colour changes. Laser colouring might be the approach taken by Topre with the Realforce, where charcoal keys are coloured to a gold-like beige with a laser beam.

<gallery widths=250 heights=187>
File:Topre Realforce 105UB -- laser-etched legends.jpg | Potentially laser-coloured legends on a [[Realforce|Topre Realforce 105UB]]
</gallery>

===Ablation===
Ablation, sometimes referred to as engraving, burns deep grooves into the surface of the keycaps. These can be left empty for aesthetic effect, or filled with colourant, termed "infill". Cherry keyboards with black keycaps are laser engraved with white infill, which protrudes above the surface of the keycap. Infill tends to stain quickly.

Ablation may also be the process used in the creation of transparent keys: the transparent plastic is covered in a (usually rubber) coating, and a laser burns off the coating to expose the transparent plastic in the shape of the required character. In this instance, the durability of the material used in the coating is the deciding factor in longevity.

<gallery widths=250 heights=187>
File:Stained laser-engraved keycaps.jpg | Stained infilled Cherry keycaps
</gallery>

===Further reading===
*Industrial Laser Solutions — [http://www.industrial-lasers.com/articles/print/volume-23/issue-1/features/application-report/laser-marking-plastics.html Laser marking plastics]
*TRUMPF Laser Technology — [http://www.trumpf-laser.com/en/solutions/applications/laser-marking/coloring-and-foaming.html Coloring and foaming]
*ROFIN — [http://www.rofin.com/en/applications/laser_marking/plastics/ Laser Marking of Plastics]