I designed Eurorack Blank Panels with vent holes.
They are available in slit and square hole types.
They are also available in 4hp, 6hp, and 8hp, respectively.

For the printed items in the photos, I used PLA for the filament material and printed them on a Creality Ender 3 S1.

This is the first design, if you have requests or suggestions please let me know.