The infill depends on the weight you want to carry with it. I chose 50% infill and with that you can easily carry a board with a few kilos of material. The more infill, the more it can handle.

I like it with black PETG so it fits/suits my room the best.

Sizes:

w: 20cm / 7.87"

h: 25cm / 9.84"

d: 3cm / 1.18"

I printed it on a 30x30 buildplate, so it fits well.

If you have a (much) smaller buildplate, place the model diagonal so it fits the buildplate nicely.

Have fun printing!