A friend of mine, known online as Johan von Elak, is going to build his own leech Greater Daemon. Although most of the bulk will be filled out with plastic of various sorts (cap bottles and the like, with lots of air pockets and strong material), he still expect the sculpting putty layer to be thick in the centimetres at places.

While he plans to buy a lot of green stuff from GSW, it would be nice if the actual filler material was of a cheaper kind, with a green stuff layer on top for surface details and smoothness.

So, ladies and gentlemen, do you have a good tip for a very cheap sculpting putty that does not require oven baking, for use en masse as filler material?