An old project from a crumby CAD class. Never got to fully test it but it looks cool and might probably work. The print default at 2mm thick. This might not be thick enough to really act as a bottle opener, but going too thick stops the 'card' from fitting inside a foldable wallet. To increase/decrease the thickness, use the scale tool in your slicer. I suggest using PETG if you can, that seemed to be nice and solid.

Features v1:

30-30-60 & 45-60-90 triangles

CM and Inch Rules

Lil' Saw

2-5mm mm holes (could be used for key chain)

6-10mm mm Hex

Untested bottle cap opener

2.5, 2, 1.5, 1mm lines (for drawing)

Various sizes of screwdriver

Features v2:

Larger saw

A single screwdriver

3-10mm

Two bottle openers (crack or 'trapezoid')

Shorter millimeter ruler

30, 45, 60, 90 degree angle cuts

Protractor-like partial curve

Key chain hole

More Practical Inspirations: https://www.thingiverse.com/thing:30273 https://www.thingiverse.com/thing:1597779