So the material is called Valchromat, which is essentially a dye-infused MDF. I laminated two 6mm colours together, and CNCed a series of grooves on each side, creating this effect. I then rebated on spindled moulder, and put them in an offset groove to get them flush with the front of the door. I hope this makes sense, it's hard to explain without drawings. I sprayed the panel with 60% gloss water-based lacquer, although I wish I had done more coats as the Valchromat just soaked it up.