Apollo metal gobos are made from an 8 mil stainless steel with a high quantity of nickel and chromium that provide longer life and image quality. They are able to withstand high heat generated from both ellipsoidal and intelligent lights. The majority of alternative products on the market are made from a 5 mil stainless steel comprised of a large amount of carbon steel that begins to oxidize (rust) and breakdown in a shorter period of time. If a magnet sticks to the pattern, it is mainly carbon steel - which means it is not an Apollo pattern.