people are using ceiling tiles, i couldn't find one where i live so i bought the balsa board.
we cover the plans with wax paper.
i'm using this one:
http://www3.towerhobbies.com/cgi-bin...?&I=LXVZ63&P=7
there is also 48" which i would buy now for 60 size airplanes.
in any case the board should be
FLAT otherwise the airplane comes out crooked.
Alex