I love the Posca acrylic markers for use in my woodshop. They're bright and opaque, are mostly permanent, but can also be removed if needed. And their 8-pack of 5M sized markers can handle most tasks. I wanted a wall-mount to keep them organized, readily available, and in full rainbow display with my other small tools. This was lucky first-try design success.

The markers fit nicely in their respective slots, but also tip out gently for easy removal. When replaced, they slide back to vertical, They are stored upside down to stay wet, and still have caps visible for quick reference.

It's a big-ish print, but should fit any standard or mini sized printer. Print it upright, with the flat base on the bed. No supports are needed. Draft mode, 3 walls, and 15% infill is plenty for a solid, clean holder.

Hopefully you'll find it useful too.