Here is my mini letterboard design,
It is portable (card-size 86x54mm) and it can fit up to two rows of words.
For the letters I used standard 20mm letters, but other sizes and custom shapes might fit as well.
I printed the frame and the grate separately. No glue needed, just press.
UPDATE 28/08/2023: New grate design (V2) for vase-mode printing! Improved the shape of the grate for a better clamping of the letters. If your printer stability/bed adhesion allows it, you can print the grate in one single part. Otherwise, try with the split version and low speed.
UPDATE 15/07/2022: Uploaded a custom set of 20mm letters. See the picture for a comparison between the 3D printed version and the original letters from a larger letterboard.
Enjoy!
The author marked this model as their own original creation.