I stopped by the Junkyard Deals Thrift Store in Gresham the other day.  The young woman who owns the store had a couple dozen of these glass slabs for sale, and she wanted $5 for the lot.  I didn't have any way to deal with a stack that heavy, so I just bought one for $2.  (She really wants to get rid of the whole pile.)

I would think these would be ideal for laying out various grades of sandpaper for tool sharpening.  Perhaps someone could buy them up and donate the excess to the Guild?

The location is:

23 NE 10th Dr, Gresham, OR 97030

and they are open four days each week, from 11 AM - 5 PM, Tue/Thu/Fri/Sat.