I used 3/4, it worked fine, probably a little more work to fair the edges of the forms to allow the strips to lay flat, but once you develop a technique it still easy enough. I'm sure it makes your mold heavier too, but it's still managable.

I'd go with what you have cheap access too.

P.

> Is there any advantage using 1/2 inch material instead of 3/4
> plywood besides cost. Is there any problems or draw backs associated
> with the thicker material. I have it already. Thanks in advance. Tony
>