The Jargon File (version 4.4.7, 29 Dec 2003):

treeware
 /tree'weir/, n.

    Printouts, books, and other information media made from pulped dead trees.
    Compare tree-killer, see documentation.


The Free On-line Dictionary of Computing (30 December 2018):

treeware

    /tree'weir/ Printouts, books, documentation, and
   other information media made from pulped dead trees by a
   tree-killer.

   [Jargon File]

   (1999-01-15)