Designed to be printed in the colors, white, black, and then red. Holes for magnets are 6mm x 3mm

https://www.amazon.com/gp/product/B07873ZCY4/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&th=1

I highly recommend having some patience and not removing this print until it cools. Mine ended up a little bowed.