Don't worry - the fine 100% polyester Superman The Man of Steel Fleece Throw Blanket won't lose its softness when exposed to Kryptonite. I suppose the greater question here is why do you have Kryptonite but I can understand your reluctance to tell! Showing off DC Comics' flagship character, the Superman The Man of Steel Fleece Throw Blanket measures roughly 45'' by 60'' and is a great way to stay warm whilst cloaking yourself in the power of the Last Son of Krypton. Hooray!