You always need to be sure your project is square. This tool can help you and you also have 4 rulers inside.

Check technical drawing i did so you can see this tool dimensions!

Print instructions

Technically you can use printing settings of your choice and also the material you like.

NB! Use "Detect thin walls" So every millimeter line will be printed!

It's 0.4 mm wide so a normal 0.4mm nozzle is abble to print it!

I printed this using a standart PLA ( Elegoo )
Layer height - 0,2 mm
HotEnd - 200C°
Bed - 55C°
Infill - 10%
NB! Use "Detect thin walls"

The rest is practically the same Prusa Slic3r Settings.

Ask me if you have problems!