After searching for advice on the interwebs, I found that many modellers out there add various setting plasters and/or powders to Sculptamold so I thought I would try just adding plain old plaster. The plaster gives the Sculptamold more "body". I do wonder if the contents have settled and the fluffy stuff is up the top and I am missing the intended balance of fibrous material and setting powder the makers intended?
Anyway, the diorama has progressed through sculpting:
Removing the card retainer/shaper:
Adding a chamfer of Pollyfilla:
Applying surface primer:
And finally my first attempt at having graduated colours to give the illusion of depth in the body of water. So far to my dismay, the gradations are more hard steps, plus the acrylic has built up unintended texture. Hopefully some actual ground scatter and another layer of paint will make things more like I intend (not sure in what order yet...):
Stay tuned for how it progresses and turns out!