Easy to Make Lightweight Foam Rocks - Kathy Millatt Modelling

I was on a mission to find lightweight, easy to make rocks.  These work well for smoother rocks or those in the background.

Beginner's Guide National Model Railroad Association

Beginners Guide Part 6: Scenery National Model Railroad Association

Easy to Make Lightweight Foam Rocks - Kathy Millatt Modelling

Spray foam for hills?

Beginners Guide Part 6: Scenery National Model Railroad Association

Scenery

Easy to Make Lightweight Foam Rocks

Beginners Guide Part 6: Scenery National Model Railroad Association

Creating Realistic Waterfall Froth and Foam

Spray foam for hills?

How To Make Cheap and Easy Model Rocks!

Easy to Make Lightweight Foam Rocks - Kathy Millatt Modelling

ET: How to paint foam to look like rocks

Spray foam for hills?