The Collaborative International Dictionary of English v.0.48:

Mandarining \Man`da*rin"ing\, n. (Dyeing)
   The process of giving an orange color to goods formed of
   animal tissue, as silk or wool, not by coloring matter, but
   by producing a certain change in the fiber by the action of
   dilute nitric acid. --Tomlinson.
   [1913 Webster]