XPS Insulation Foam
Overview
Extruded polystyrene (XPS) foam board — pink/blue insulation foam. Very cheap, fast to cut by CNC. Used for architectural models, theater sets, and cosplay armor bases before coating.
Properties
Pros
- Extremely easy to machine
- Very lightweight
- Inexpensive
- Good for prototyping and lost-foam casting
- No grain structure
- Holds reasonable detail
Cons
- Messy — generates static-charged beads
- Not durable
- Can melt if spindle speed is too high
- Static cling makes cleanup difficult
- Not structural
- Limited to low-stress applications
Best For
- Architectural models
- theater scenery
- cosplay armor bases
- terrain models
- insulation with decorative cuts
Avoid For
- Structural use
- outdoor exposure without coating
- any acetone-based paint (dissolves XPS)
Laser Compatibility
XPS foam melts and vaporizes rather than burning — very low power needed. CO2: cut 10mm at 500mm/s 15-20W; engrave 600mm/s 10%. Diode: cut 500mm/s 30-40%; engrave 600mm/s 20%. Produces styrene fumes — strong ventilation mandatory. Results in clean sealed cut faces. Do not use high power — causes excessive melting and fumes. Excellent for RC plane wings, prop fabrication, and model terrain.