My plate fractured as I was trying to desperately remove a part, so I had this one cut using a waterjet. I included the SolidWorks files in case you want to modify.

UPDATE: got a build plate waterjet from glass and it was one of two best upgrades to the Rep 2 and has had a substantial positive impact on my build experience. The other best is definitely this: http://www.thingiverse.com/thing:42250

Cut from glass or acylic using waterjet or otherwise. If you use glass then you will need to use tape but in my experience the tape sticks very nicely to glass.