(AK104) AK Interactive release Modelling Grey Putty. This high quality acrylic putty is a water based one component polyurethane product designed for modelling. Comes in two variants - extra hard white putty and grey putty of standard hardness. It is a superfine filler with excellent adhesive and sanding properties. The product is water based and does not contain strong smelling chemicals. Does not shrink with drying. Can be cleaned off with water.