Hello guys!

I have only tried to make a diorama once, and I used Plaster of Paris for the ground work.
I wanted to make it look like dirt, but it was white. I tried painting it, but it only looked like cow poo-poo. I was forced to create a snow diorama because I could not simulate dirt...

NEED HELP!

I have never had that problem you mention - it doesn't sound like any fun.

The way I do groundwork is this, on my already prepared base.
1. Use old packaging styrofoam and hot glue or resin it into place to build up the large hills or mounts.
2. Cover it with Celluclay - this is a brand of paper machee. It's a gray dusty powdery stuff all you do is add water and mix it up. Once mixed it turn turn into a pastie kinda stuff. Spread this out over your base.
3. I let it dry totally. It starts out dark gray and lightens as it drys, depending on thickness, water quantity and temperature it may take a while (days). I try to limit the thickness to reduce this time. This is where I embed any exposed rocks using kitty litter or rocks from the back.
4. If I plan on exposed dirt I will go out back and get some fine dry dirt. I then mix it with white glue and water. Just mix white glue with water about 50/50. You can add the dirt now or spread the waterglue where you want it then sprinkle the dirt on top. Let it dry, 24 hours usually.
5. I then paint the ground work the browns and tans and grays I plan on using. Lots of shades not of highlights and shadows.
6. I then mix white glue and water and sprinkle on static grass. As it is drying I 'strighten' the grass with a dry brush, by blowing across it, and by tipping the base upside down (tipping is done after the glue sets a bit).
7. Repeat any previous step to enhance the look of the base.
8. I paint the grass (if desired). I dry brush lightly to highlight.
9. Ground work is done, now for trees shrubs etc.

Don't forget to plan the ground work - build in any AFV tracks during step 3. Make the necessary foundation holes for any structures or tree holes etc.

Hope this helps.

Here's what I do (it's cheap BTW)...

I build up elevated ground by taking paper and making it into balls. I then take masking tape and tape them to my base. I cover up any holes with masking tape. Prime the entire thing. Then I get some sand (if you live in a desert, or near a body of water this should be very easy to find). Sift all the extra debris out (larger rocks, twigs, bugs, grass, etc.) with a screen. Be sure to get ALL of the non-sand stuff out. Then mix it with color of acrylic paint you want the dirt to be. Mix it until you get the consistency of freshly made Malt-O-Meal, maybe a little thicker. This is what I call "Sandpaint". Now use a brush to "dab" it on. Fill in cracks then go over the entire area, covering all the masking tape with this stuff. Let it dry and then maybe go over it again with another layer, perhaps of a lighter shade, and then add your bushes, grass, etc. The masking tape makes it easy to insert field grass. Actually, before adding your bushes and stuff, you might want to paint blotches of different shades of dirt. Since some areas have richer dirt than others it would look more real that way. Do it at random though.

I tried plaster before, and that works well. Don't just paint it in one even colour, but add streaks and blotches of darker/paler paint through the surface of your dio. Mix "sand, small pieces of rubble or real diorama ground stuff through the paint to create texture. Works well.
Plaster dioramas have 2 disadvantages, though :
- they can break
- they weigh a ton if you make a large dio
(and when I was a kid my mom wasn't too keen on my messing with plaster in the house !)

Try lightweight techniques as discribed above to make large terrain elevation, you can use plaster if your only purpose is to bring some texture in the flat dio surface.

If you don't like the plaster of paris method....the other thing you can do is find someone you know that works at a hospital....and get them to get you the plaster strips that they make casts out of. Take your wood base, use your styrofoam or whatever you want to be the base of hills and such....take the cast strips....run them through water the same way they would if they were putting a cast on your arm or leg...and then apply to the base, you can use as little or as much of it as you want, while its still wet, you can apply sand, gravel, static grass, etc, etc, and once its dry, just turn upside down to take off the excess. Paint and highlight if you want...as needed. Very simple to do!!!