Plastic is the best you can put them in the dishwasher and they don't damage knives. I can't see how a stone one wouldn't wreak a knife. Also if you can't get a granite counter top absorbs water and oil why wouldn't a cutting board do the same ?

I would not use wood just because I can't put it in the dishwasher. Ok I can and have but they don't last long when I do.
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Matt