Definition: lightfast - Fade resistant to light especially ultraviolet rays. Usually refers to the dyes or pigments used in fabric dyes and artists materials as well as colored papers. Items which are lightfast will not fade as much as those with pigments known to fade in ultraviolet light. Collectibles which are made of lightfast materials will require less specialized display conditions than those where dye and pigment information is either not known or is known to be less lightfast.
Alternate Spellings: light-fast
Examples: If an item is not lightfast it should be displayed behind protective glass and not exposed to sunlight.

