It’s oil from your skin. The pretty heat colors on the stainless steel are a result of oxidization of the metal, which reaches different depths as it gets hotter - but if the metal is heated rapidly enough, or to a low enough temperature the steel will begin to discolour before the oils burn off. Since the area with skin oil on it has a barrier between the metal and the oxygen (the oil), the outline of the hand is prevented from gaining a color and thus it shows up like this.
It’s neat to see in person, with a light touch you can easily see the distinct patterns of a person’s fingerprints outlined in some really pretty colors.
It’s oil from your skin. The pretty heat colors on the stainless steel are a result of oxidization of the metal, which reaches different depths as it gets hotter - but if the metal is heated rapidly enough, or to a low enough temperature the steel will begin to discolour before the oils burn off. Since the area with skin oil on it has a barrier between the metal and the oxygen (the oil), the outline of the hand is prevented from gaining a color and thus it shows up like this.
Ah ok that was interesting to learn and also that it’s just oils from skin
It’s neat to see in person, with a light touch you can easily see the distinct patterns of a person’s fingerprints outlined in some really pretty colors.