The original signs were made using Plexiglass, and a stencil for the wording "AMBULANCE", or whatever the customer wanted, using translucent red (or other color specified by customer) paint on the back side of the Plexiglass. Once the contrasting color translucent paint dried, then the entire rear surface was sprayed with white translucent paint. I have a local paint shop that has done them in the past, however, he said that I would have to pay for the paint if I wanted them done again. Told me that the paint was expensive, and has a short shelf life, and that since the demand for this type of an item is small, he stopped doing them.