Copper, bronze, brass, and steel PLA — prints that look and feel like real metal. Here's everything you need to get stunning results.
Nozzle Temp
190–225°C
Bed Temp
50–60°C
Nozzle
Hardened steel 0.4mm+
Difficulty
Moderate
Metal-filled filaments are standard PLA (or sometimes PETG) blended with 40–85% real metal powder — copper, bronze, brass, iron, or steel. The metal particles give the finished print real weight, metallic sheen, and the ability to be sanded and polished to look indistinguishable from cast metal.
They're decorative, not structural — metal-filled filaments are weaker than pure PLA and shouldn't be used for functional parts under stress.
| Type | Look | Polish Result | Price |
|---|---|---|---|
| Copper-filled | Warm reddish-orange | Bright copper sheen, greens with patina | $45–70/kg |
| Bronze-filled | Golden brown | Rich antique bronze, aged look | $45–70/kg |
| Brass-filled | Yellow-gold | Polished gold/brass finish | $50–75/kg |
| Iron-filled | Dark grey | Can rust with water — authentic aged iron | $40–60/kg |
| Steel-filled | Silver-grey | Polished steel look, highly magnetic | $50–80/kg |
| Setting | Value | Notes |
|---|---|---|
| Nozzle Temperature | 190–225°C | Higher end for high metal-content filaments |
| Bed Temperature | 50–60°C | Standard PLA bed temp |
| Print Speed | 25–40 mm/s | Slower than PLA — metal particles need time to flow |
| First Layer Speed | 15–20 mm/s | Critical for adhesion |
| Nozzle Size | 0.4mm minimum (0.6mm recommended) | Smaller nozzles clog from metal particles |
| Nozzle Type | Hardened steel REQUIRED | Brass nozzles wear out within 1–2 spools |
| Cooling Fan | 50–100% | Standard PLA cooling |
| Retraction | Reduce 20% vs standard PLA | Over-retraction causes particle accumulation |
| Layer Height | 0.15–0.2mm | Thinner layers = smoother finish before polishing |
Post-processing is where metal-filled filaments shine. Without it, they look like grey/brown plastic. With it, they're stunning.
Sand with coarse grit (120–220)
Remove layer lines and surface roughness. Sand along lines first, then across. Water-sanding works well here.
Progress through fine grits (400→800→1500→2000)
Each step removes scratches from the previous. Don't skip grits. Wet-sanding with 1500+ gives mirror-prep surface.
Polish with metal polish
Apply Brasso, Flitz, or Mothers Mag Polish on a cloth. Circular motion, then buff off. Repeat 2–3 times for maximum shine.
Optional: Chemical patina
Copper/bronze: apply liver of sulfur solution for green/brown aged patina. Iron: water exposure + salt = real rust. Very dramatic results.
Seal with wax or lacquer
Protect the finish. Renaissance Wax for a natural look, clear lacquer for permanent protection.
| Brand | Types Available | Metal Content | Notes |
|---|---|---|---|
| ColorFabb | Copper, Bronze, Brass, Steel | ~40% | Premium quality, consistent results |
| Polymaker PolyMetal | Copper, Iron | ~60% | High metal content, heavier feel |
| Proto-Pasta | Copper, Iron, Steel | ~50–85% | Highest quality, iron actually rusts |
| eSUN | Copper, Bronze | ~40% | Budget option, good for beginners |
Hardened nozzle mandatory. Standard brass nozzles wear out within 100–200g of metal-filled filament. Don't skip this.
Brittle prints. Metal-filled PLA is weaker and more brittle than standard PLA. Thin sections snap easily — design with thicker walls (minimum 2mm).
Heavy. A 200g printed object in copper-filled filament can weigh 400–600g. Account for this in designs with thin bases.
Store sealed. Metal particles can oxidize. Keep in sealed bags with desiccant between uses.