FDM vs Resin: Differences Between the Two 3D Printer Types
Contents
Almost every printer used at home relies on one of two technologies. FDM printers lay melted plastic filament down through a nozzle, layer by layer. Resin (MSLA) printers cure liquid resin with UV light. FDM stands out for functional, large and durable parts, and resin for small parts with very fine detail.
How do they work?
FDM
Filament is fed from the spool to the extruder, melts in the hotend and comes out of the nozzle as a thin line. The toolhead traces the shape of each layer, then rises one layer and continues. More on this in What is a 3D printer?
Resin (MSLA)
A vat with a transparent film at the bottom holds liquid resin. An LCD screen under the vat projects the shape of each layer into the resin with UV light. The lit area hardens and sticks to the build plate above. The plate rises a little after every layer. The part grows upside down on the build plate.
Comparison table
| Feature | FDM | Resin (MSLA) |
|---|---|---|
| Detail | Good, layer lines visible | Very high, smooth surface |
| Typical layer height | 0.1–0.3 mm | 0.025–0.05 mm |
| Build volume | Usually larger | Usually smaller |
| Materials | PLA, PETG, ABS, TPU, nylon and more | Standard, tough, flexible and castable resins |
| Strength | Good for functional parts | Standard resins are brittle, special resins are better |
| Post-processing | Remove supports, optional sanding | Washing, UV curing, remove supports |
| Smell and safety | Low with PLA, ventilation for ABS | Resin is irritating, gloves and ventilation are a must |
| Maintenance | Nozzle, bed, mechanical parts | FEP film, LCD screen, resin vat |
| Material cost | Low | Medium to high |
| Cleanliness | Easy | Messy, needs IPA and waste handling |
Strengths of FDM
- Material variety: A wide range from PLA to TPU and from ABS to carbon-fiber-filled nylon. See PLA vs PETG vs ABS.
- Functional parts: Brackets, holders, spare parts and durable mechanical parts.
- Large parts: Build volumes are usually bigger.
- Easy to use: When the print is done the part comes off the bed, and no extra chemical processing is needed.
- Low running cost.
Strengths of resin
- Outstanding detail: Miniature figures, jewelry models, dental models and small mechanical details.
- Smooth surface: Layer lines are almost invisible.
- Speed on small parts: Because the whole bed is exposed at once, fitting many small parts onto the same layer does not lengthen the print.
Challenges of resin, and safety
Resin printing takes extra work and care:
- Personal protection: Uncured resin on skin causes irritation and, over time, can lead to allergic sensitivity. Use nitrile gloves and eye protection.
- Ventilation: Resin fumes are irritating. Run the printer in a ventilated space away from where you live.
- Washing and curing: After printing, the part is washed in isopropyl alcohol, or in water for water-washable resin, and then cured under UV light.
- Waste: Do not pour liquid resin or resin-contaminated IPA down the drain. Harden the contaminated liquid in sunlight or under UV and dispose of it according to local waste rules.
- Ambient temperature: Resin thickens in a cold room (below about 20 °C) and prints can fail.
Challenges of FDM
- Layer lines stand out on finely detailed figures.
- Problems that need first-layer work, calibration and tuning are more common. See Troubleshooting.
- Materials like ABS need an enclosure and ventilation.
Which one is for you?
| What you need | Suggestion |
|---|---|
| Brackets, boxes and spare parts for the home | FDM |
| Miniature painting, tabletop game figures | Resin |
| Prototypes and engineering parts | FDM |
| Jewelry, casting models | Resin (castable resin) |
| Large costume parts | FDM |
| Use together with children | FDM (PLA) |
| First printer, general purpose | FDM |
Many people start with FDM and add a resin printer later for fine-detail work. For more on the selection criteria, see How to choose a 3D printer.
Are resin parts durable?
Standard resins are hard but brittle, and they can crack on impact. "Tough" or "ABS-like" resins are more durable. Still, for functional, load-bearing parts FDM usually gives better results.
Can I use a resin printer at home?
Yes, but in a well-ventilated place away from where you live, with protective equipment such as gloves and eye protection. Pick a spot that children and pets cannot reach.