he·li·o·type 
(hēlē-ə-tīp′)
(hēlē-ə-tīp′)n.
1. A photomechanically produced plate for pictures or type made by exposing a gelatin film under a negative, hardening it with chrome alum, and printing directly from it.
2. also he·li·o·typ·y (-tī′pē) The process of producing a heliotype.
heli·o·type′ v.
he′li·o·typic (-tĭpĭk) adj.