CNC Milling: materials

Extruded polystyrene (Blue Foam)

Recommended for people new to milling and for most surface milling jobs. We like this product to do a first run before using the final material.

pros: inexpensive, lightweight and transportable, mills quickly with inexpensive tools, paintable with gesso and water-based paints.
cons: dimensionally unstable so must be mounted to a more rigid backing, color may require painting, will not withstand significant wear and tear.
sources: available locally at construction materials suppliers. (used for isolation). (Examples: Brico; Mpro: Avenue du Port 67 1000 Bruxelles (close to iMAL)

Polystyrene foam with a 3mm radial router

Extruded polyurethane
pros: dimensionally stable, uniform color, homogenous material, mills quickly with inexpensive tools, capable of being milled into thin surfaces
cons: relatively expensive, limited sizes
sources: available online.

Landscape with High-density foam

Plywood

pros: withstands wear and tear, layers create interesting effect (but often distracting) dimensionally stable
cons: potentially expensive, may require specialized cutting tools, layers are of different quality and may contain knots.
sources: available locally iconstruction materials suppliers . (Examples: Brico; better quality at Vanhumbeeck (http://www.vanhumbeeckfreres.be) ..)

12 mm Multiplex with a 3mm cutter

MDF (medium density fiberboard)
pros: dimensionally stable, uniform color, homogenous material
cons: requires expensive cuting tools, creates hazardous dust.
sources: available locally at construction materials suppliers. (Examples: Brico; better quality at Vanhumbeeck (http://www.vanhumbeeckfreres.be) ..)

Solid wood

Solid wood materials come in a range wide range of hardnesses with varying grain qualities.
pros: looks nice, will withstand wear and tear
cons: can be expenseive, not dimensionally stable, limited sizes, may require expensive cutting tools. More dense woods may require more complex milling strategies and can be slower operations.
sources: available locally in some construction materials distributors. (Example: Vanhumbeeck (http://www.vanhumbeeckfreres.be) ..)