Krypton is a noble gas that prefers to stand on its own and rarely plays with others. When stimulated with electricity: this natural element glows brightly and reliably. From light sabers to kryptonite: Krypton's unique green spectra have inspired many pop culture and sci-fi favorites: including our own Krypton Thinking Putty! White by day: this putty glows the signature green in the dark. Each tin includes 1/5 lb of Krypton Thinking Putty huge handful for tons of fun.