GMK Prussian Blue

GMK Prussian Blue is a custom keycap set to be manufactured in the Cherry profile by GMK Electronic Design GmbH. These MX-compatible keycaps will be made from ABS plastic and doubleshot legends (with UV front-print where needed). GMK Prussian Blue uses a simple color scheme with a GMK stock white (CP) for its legends and a custom color for the base: RAL 230 20 20 (Preußischblau).

This keycap set will be sold via Group Buy preorders, with the sale estimated to occur in Q3 of 2022.

Prussian Blue

Prussian Blue is a chemical compound originally discovered in Berlin at the turn of the 18th century. It has been used in a variety of settings from art (Japanese woodblock painting) to architecture (a traditional blueprint dye) to medicine (a treatment for heavy metal poisoning).

Prussian Blue was also used for nearly two centuries to dye the military uniforms of the Kingdom of Prussia. The RAL standard and this keyset draw from this darker variant, and GMK Prussian Blue’s kitting takes further inspiration from the history of the Kingdom of Prussia itself.

The Kingdom of Prussia

The Kingdom of Prussia was established circa 1701 and existed until approximately 1918. Its borders changed frequently, with many of its parts split into separate enclaves and exclaves. Though it was ruled by a German-speaking monarchy, its reality was far more diverse, including regions of Germans, Poles, Lithuanians, and Silesians. For most of its existence, however, the majority of Prussian territory lay within the current borders of Germany and Poland.

GMK Prussian Blue Deskmat Draft
Prussian borders circa 1820 superimposed over modern central Europe.

As a reflection of the Kingdom’s multilingual and multicultural footprint, GMK Prussian Blue will offer two distinct base kits: one German and one Polish.

Base Kits

GMK Prussian Blue will offer both a Polish/US Base kit and a German base kit.

The Polish / US Base kit will use the modern “Polish Programmers’ Layout,” whose similarity to US ANSI allows it to also serve as the primary base kit. Its modifier key legends will be a mix of icons and English language modifiers. Especially when paired with the Spacebars addon, it provides physical compatibility for very wide array of boards, including a majority of 40% boards as well as rarities like the Vortex Race 3 and Boardwalk.

The German Base kit will follow a German QWERTZ standard layout while also providing a QWERTY option. Its modifier key legends will use a mix of icons and German language modifiers, with most following the style of boards sold by GMK’s own Uniqey storefront. Its physical support for nonstandard keyboard layouts is intentionally more limited to control costs.

These two base kits also pay homage to my own dual US / German citizenship. This kitting is not final, and I am open to suggestions, though I’m unlikely to make major changes to either base kit.

Child Kits

The Spacebars kit provides a wider range of spacebar sizes, particularly for split & smaller keyboards. It also includes a 6u spacebar key with an off-center stem, allowing it to fit classic Cherry G80-1800 models.

The UK / Subless kit, when paired with the Polish / US Base kit, offers a means of more accurate UK & US localization support (i.e. without the Polish sublegends).

The Nordic kit, when paired with the German Base kit, provides alpha localization for Denmark, Sweden, Norway, & Finland.

The UK / Subless and Nordic kits may be combined into a single International kit. However, if it is feasible, I would like to keep these two kits separate, as I believe they individually provide a better value to the buyers in those locales. Any such changes will be announced prior to the Group Buy.


To be announced later. I have already been in discussion with US, UK, and EU vendors who are positive on the set and who are willing to provide support for my unorthodox kitting.

Board Renders

All renders provided by Manzel.

Renders may contain inaccuracies and should not be considered the final authority on the appearance of the caps.

Bear – Polish / US

Bear 65% split Alice-like keyboard by Jacky.

Mech27 TKL – German

The Mech27 TKL, depicted with a custom color and the German base layout.


The deskmat design is still a work in progress. It will be licensed under Creative Commons Attribution Share-Alike 3 (full license text, sources at bottom of this page).


I am in contact with two potential suppliers for metal artisans and hope to enlist other artisan manufacturers to offer small-batch color-matched collectible caps.


As stated above, GMK Prussian Blue will include one new custom color (RAL 230 20 20). Its legends will be GMK stock white CP. Below is a diagram that compares the estimated RGB hex colors of several prior and upcoming GMK and Signature Plastics keysets with those of GMK Prussian Blue.

GMK Prussian Blue Color Standard Comparison


  • Thanks to my amazing wife, who has remained supportive even as my home office fills with more keyboards, keycaps, color standards, and cardboard boxes.
  • Thanks to my adorable daughter, who brings me such joy.
  • Thanks to Afresh & konstantin for their immense help with getting the ogoneks right.
  • Thanks to Manzel for his professionalism and renders.
  • Thanks to hunghingdailo, who gifted me with a brilliant logo.


The following works, which were used to design the deskmat, are licensed under Creative Commons Attribution-Share Alike 3 (full license text):