Hello, I have been wondering about using foam board(the kind with paper on each side) for a diorama base. The two dio's I have done are with underlayment board mounted inside picture frames which makes for a sturdy yet heavy base. And my question is has anyone used the foam board inside a picture frame before and how did it work for you? Also the dio that I am thinking on using this for has a river on it would the water products affect the foam? Should I just stick to the underlayment? Whats everyone think? Confused Kevin

kevin - I've used that an just plain foam for bases. One thing I do is coat the whole thing with wall putty, foam board trends to warp when covering materials like Celluclay dry and shrink but other than that it's worked okay for me , then you can put it in a frame or for odd sizes use coving material to cover the edges

There was an article on the foam board a while back. I used it, and followed the simple rule that to prevent warping of the board you will need to make a 50/50 solution of white glue and water. Put a thin coat of it on the paper and all to dry overnight. Then apply any putty or plaster you want. The glue mixture acts as a protective membrane on the paper.

My suggestion would be instead of using the foam core, I would use The pink insulation foam, the kind you would use to insulate your house it comes in a 4'x8'sheet (plenty for future dio's) and comes in a variety of thicknesses. You wouldn't have to worry about warping at all and if you are planning a water feature, it is easy to carve realisitcally for the banks. You can glue it , and stack it to get your desired thickness to create "hills" and "banks". The advantage is you still have great strength in the base and you don't have to deal with the paper laminated to the foam. Give it a coat of house hold acrylic paint and you are ready to start your ground work (the acrylic base coat helps seal it as petroleam based mediums will "eat" ANY styrofoam . I use it exclussivley, for the ease, convience, and cost effective. Just my opinion and another option for you to think about.

We used FCB on this:
it was easier in a 1/4"=10'-0" scale....... for the elevations. It's covered in Plastercloth afterwards.

I'm really cheap! I visit construction sites (after the workers have gone home) and collect up all the scraps of pink foam lying around. There's always chunks and slabs of various thickness being tossed away. As an alternative, you can use white packing foam which comes in various shapes for the item they were meant to protect. With some imagination some of these shapes can become concrete bunkers!