> I have used all the materials mentioned for forms. I can't say that any of
> them are ideal. I have yet to find the "ideal" form material. I
> generally use what I have available or MDF.

> Elmers would have greater wrinkling problem. I've been using a 3M spray
> adheasive that comes in a black can. It has not caused wrinkling for me.

I have to second's Nick's use of the "3M" brand, I had no problems getting the patterns to stick well.

When i built my Gboat, I bought 3/4" 7layer shopgrade spruce or douglas fir plywood on sale for $35 Canadian and only used about 3/4 of the sheet. Held staples good as well as the odd drywall screw w/o splitting. I used 7/16" flakeboard for the breakoff forms in the cockpit area and wouldn't do that again.

Greg