Pretty much carbon copy of old door studs as found across ironmongery sites. approx 22mm x 22mm x 14mm high. Print, screw into wood, then seal the screw hole with filler, blue-tack, toothpaste (yeah this actually works!), pva glue…anything really. Then paint / spray black. Best results would be to prime coat them, then paint with Hammerite type paint.