Derivation of the word oaktag

[Bapopik at AOL.COM]

   16 January 1949, NEW YORK TIMES, classifieds, pg. F14:
PAPER PRODUCTS...oaktag board.

   2 June 1963, NEW YORK TIMES, classified, pg. 155:
Oak tag all colors...GEM PAPER 594 Bway NY.

(I don't have time for an in-depth search because I'm leaving the country within 24 hours...COMPLETELY O.T.  _Now_ my Nets beat the Lakers!--ed.)