EPS polystyrene expanded (foam)
The most suitable material for the production of terrain and mass models. Foamed polystyrene is very simple to process and cut, for example with a wire cutter. However, it is not possible to adhere with any adhesive, most of glues will destroy polystyrene. Often it is enough to join polystyrene with ordinary pins, stick polystyrene for example with Herkules, or special UHU POR polystyrene adhesive, which also dries faster. It is produced only in white or black, and it is necessary to use dyes or sprays on water base if necessary. The biggest advantage is availability and affordable.
XPS polystyrene extruded (hardened)
Same use, bonding, dyeing and cutting as a expanded polystyrene, it's just firmer, smoother "no bullets" and more expensive. Compared to EPS, it is also produced in small thicknesses from 1mm, while the foam polystyrene is the thinnest 10mm. XPS can also be found in various distinctive colors, but the most common color is gray. Ideally it would be a white color, which is unfortunately not produced and can not be obtained anymore.
EPP polypropylene extruded
On the first look it looks like a classic expanded polystyrene, but it is very flexible to "rubber" and therefore does not break at any bending. EPP bonding is possible with any contact and second adhesive. It is produced in thicknesses from 3mm and mostly in white color. In the case of dyeing, it is necessary to use the solvent-free paints again, that is to say water-soluble paints.