Very few effective shielding materials against psi have been discovered outside of extremely expensive directed energy enclosures, but nullglass is one of the most reliable. It is a smooth, brittle, translucent red-purple material that is opaque to the majority of analytical techniques known to human science, and its means of manufacture is a closely guarded industrial secret. Currently only a handful of individuals are able to produce the substance, and generally only in low quantities. Its effect on psi-users is immediate and drastic: an operant in physical contact with nullglass will find their active effects slipping away and be rendered unable to manifest more.