Terraforming Mars + Colonies + H&E Box Insert

I was looking for a box insert for the game Terraforming Mars that is compatible with sleeved cards but could not find any. Therefore I decided to design my own. My insert is compatible with the base game and the two extensions Colonies and Hellas & Elysium.

I provide all my models for free, if you want to support my work, you can buy me a coffee!

For printing this model you additionally need 60 round magnets with the dimensions 4x2mm. I would recommend to insert the magnets with the following pattern, otherwise the boxes might repel from each other:

There are two main versions of the models available, a closed version that is intended to embed magnets within the print using a pause during the print and an open version where the magnets can be glued in place after the print is finished. In addition the model is available in 3 different tolerance versions for the magnet opening ranging from 4.1 mm to 4.3 mm. I recommend to print the magnet tolerance test first, to check which size fits best with your magnets. The number of squares above the opening refer to the number after the decimal. (one square is 4.1 mm etc.)

The logos on the lids are not visible directly, but the geometry is part of the STL files. Easiest way to color them is to select the fill option with edge detection and slowly moving the mouse over the lids. This way you can easily fill the logos with the color you like. 

Additional info about spacers: As per user request I added multiple optional spacers that can be printed if you do not own all of the extensions. I would still recommend to print the original parts if you think you plan to every buy the extensions. If you decide to use the spacers you can find the model in the Optional Spacers folder. There is one spacer for the colonies holder, for the colonies parts. There are two variants available for the card holders. You can either print a larger variant of the default spacer or you can print the card holder spacer in addition to the default spacer.

Disclaimer: The bambu studio profiles provided have been created to my best knowledge, but I did not actually print these. I configured them the same way I did it in Prusa slicer, utilizing adaptive layer height etc. Please let me know in the comments if the profiles did help you printing my model.

The insert is designed to fit the player mats of Sean Parsons.

Changelog:

19.01.2026: Fixed typo in Card_Holder_Corps

25.08.2025: Fixed typo on Card_Holder_Corp_Era