Cherry MX keycap with indent

Indentation

Heat a cup head bolt or a similar rounded object to approx 80°C or higher (by putting it in a cup of hot water for example) and push it slowly onto the keycap to form the indent.

I used a M6 (I think DIN 603) cup head bolt.

Labeling

For the green button I used the z-hop method, the rest is toner transfer.

The black keycap is a two color print (black and white) with a white inlay to get the white number/text with the toner transfer technique.

Inspired by the keypad in Star Wars Andor S1E2, minute 16:10.

More on the toner transfer technique: r/FDM_TonerTransfer