After the irregular weather shifts and family commitments of the last couple of weeks, I managed to finally get the paint test done on the rock. After painting it looks like...... a rock! We have a succesful test, although I now want to have a play with gloss varnish and flock to see if I can get a realistic wet and algae like finish to the lower areas.
To paint them I used the washing/leopard spot technique also generally employed by railroad builders, I really like the finish although it's a little disconcerting early on as you can see in the first couple of pics below. The plaster finish softened too while it was wet but thankfully hardened back up as it dried.
Initial colour washing.
Grey/black washes start to layer up.
The black got a little strong so I added a grey layer again after this to soften it a little.
Once dry, place with something stone to see how it compares...
Now to get the rest done.