I’ve shared a lot of tutorials about using EVA foam to make armor. The beauty of EVA foam – besides being affordable – is its versatility. You can make the substance look like plastic, like metal, and like leather. Cosplayer and maker Andrew Cook, also known as DaFrontline Trooper, works extensively with the material. He’s recordered several tutorial videos on his YouTube page that demonstrate how to build armor and finish it, and in this video, he explains how to make it look like leather. It only takes foam, a heat gun, paintbrushes, and orange and white paint. A commenter also suggests this method:
To get a much better texture and a real look of leather, use tin foil, scrunch it up then flatten it out, not to much, keep the ridges in it and place over the foam, and with a hot iron, iron onto the foil over the foam making sure NOT to melt the foam, this technique gives a real leather look leaving an imprint in the foam, then use paint to correct the color.
via Mohrigan Cosplay