The A.D.A. sign could be made in several different ways, they could be casted, molded, or engraved, when they are engraved they are made of two sheets of solid color, usually the bottom one is thicker that the top layer. They has to be made with two engraver the computer engraver drill the holes with a special Braille software, little balls are drop in the holes and hammered in, the top layer with the information in English and perhaps a frame around are cut with the laser engraver, and the two parts put together with glue or double faced tape, there are many combinations of colors. The cost is the double of regular plastic signs because it is double work.
