Hi and thank you for your question. It is custom and made to order. Any glass supplier can make this for you. Back painted means that you pick the paint colour you want to show through the glass and they will pain the back of the glass before installing it on your wall. If wanting a white colour we believe using sapphire glass is the best since it is the whitest glass on the market and shows less of the natural green tint that glass has. Hope this help and please don't hesitate to ask if you have any further questions.