Currently, I use HIPS Extrafil "Natural" from Filamentum. It is polystyrene, and can be glued with normal modelling glue like Revell Contacta. I tried other HIPS materials from other brands. Others are softer, and easier to sand smoth after printing. But those softer filamenst tend to stress crackings with higher objects while cooling down, probably due to shrinkage. With the Filamentum material, I have no real problems with shrinkage so far. The most difficult part for me is to persuade the material to stick on the printing plate. Therefore, I use a special foil (BuildTak). Check out "our" thread about 3d printing .