In this part of the tutorial we start the building of the diorama. We build the main structure of the terrain and then add some basic colors to it.

We are going to be pouring something called "realistic water" into the diorama. It is a liquid that hardens into a shell that looks like water. It's really amazing stuff. But, it starts out as a liquid you need to pour into the diorama so you have to seal off the base to avoid leaks.

I sealed the base, particularly the cracks and edges, with Mod Podge.

A simple sketch is all you need. On my drawing you can see the major elements. The billboard will go on the upper right. There is a river and waterfall on the upper left. And most of the lower left quadrant is water.

The back part of this diorama is where the terrain is higher so I created a cardboard support for this.

Use crumpled newspaper and masking tape to flesh out the terrain.

Start with the larger sections then move on to smaller detail areas. The river bed is a good place for small detail pieces.

It will dry into a hardened shell. And it doesn't take long, maybe an hour.

Once it is dry paint broad colors on the diorama. Consider the various areas you have and what color they will be. This is an undercoat. You will be covering all of this with terrain materials.

For my diorama, almost finished with the base painting, you can see several broad swatches of color. Dark green, light green, sand, blue and silver. Remaining to paint is the waterfall and river.

Then do some detail painting where there will be very little terrain. This would mostly be on the cliffs and rocks.

Let's continue and add terrain textures

You can buy rolls of plaster cloth on Amazon:

Plaster Cloth