I can't find anything about ON-GRADE anywhere.
I went to Columbia's site could not find anything.

Don't know what it means.
see: http://i.imgur.com/eqrXfhj.jpg

Anyone have an idea, got it from HD a few months ago for 51 cents before
they stopped doing 51 cents..

The 51 cents were for the remnants of what someone already paid for. ie
they bought a full sheet but only needed a portion of it and had it
cut.. the rest would go to .51 or 1.02.. no more. Now HD wants 70% of
the retail value.

--
Jeff