You can now buy metallic layered perspex that when engraved shows the rear colour thru. You can also get reverse laminate where the front stays clean and you engrave in reverse on the back then fill in with paint, so you get all the engraving on the back and a clear front so it can't mark or rub off.






These were done with a laser but no reason why they could not have been done with a CNC router, in fact that's all i had until I got the laser.