Made of aluminum foil with a pressure sensitive backing which adheres to most any surface that is clean and dry. The facing is made with a special anodize process which will resist sun fade-out and surface abrasion. These are the original placards that went into production in 1969 and have been copied, with less quality, by others. The placard material and anodize process meets Federal Specifications GG-455B and MIL-P-15024-B. The adhesive meets MIL-P-6906-A. Unless otherwise specified the placards are made of soft aluminum.