Resin printing (MSLA / LCD) plays a different game than FDM: instead of laying down molten filament, it cures a liquid photosensitive resin layer by layer with UV light. The payoff is a level of detail and surface finish no nozzle can match. The trade-off: a messy, toxic process that forces a mandatory post-processing stage. Here's the full workflow, no blind spots.
Resin is maximum detail (miniatures, jewelry, dental, precise prototypes) at the cost of safety and post-processing. It isn't "a better FDM": it's a different craft.
In brief
A resin printer projects each layer's image, through a UV LCD screen, into a vat of liquid resin; the light cures the material and the build plate rises layer after layer. The part comes out covered in uncured resin: you must wash it (isopropyl alcohol or water) then cure it under UV. All of it with gloves, a respirator and ventilation — liquid resin is an irritant and gives off volatile compounds.
How it works
Almost all consumer machines are MSLA (Masked Stereolithography), also called "LCD." The principle:
- The vat holds the liquid resin; its bottom is a flexible transparent film (FEP or nFEP).
- Under the vat, a monochrome LCD screen (4K to 16K today) masks a 405 nm UV source. For each layer, the screen shows a black-and-white image: light only passes where the resin must cure.
- The build plate dips into the vat, right up to the film. The layer is exposed (often 1 to 3 s on fast screens), the lit resin polymerizes and bonds to the plate.
- The plate lifts (the part "peels" off the FEP film — the peel), then drops back by one layer height of 20 to 50 µm. Repeat, layer after layer.
Printing therefore happens upside down, the part growing upward. In-plane (XY) precision isn't tied to a nozzle but to the screen's pixel size (≈ 18–24 µm): hence the characteristic fineness.
In FDM, speed depends on how much there is to extrude. In resin, the whole layer prints at once: one figurine or a hundred figurines across the plate take (nearly) the same time. Resin loves a full plate.
Post-processing
This is the step beginners underestimate. Fresh off the plate, the part is sticky, covered in uncured resin and not yet solid all the way through. Two steps are mandatory:
- Washing. Remove the liquid resin with isopropyl alcohol (IPA) — or water for water-washable resins. Allow 3 to 10 min, ideally in a wash station (agitation/ultrasonic bath). Then let it dry.
- Curing. A controlled UV exposure (cure station, or UV lamp) polymerizes the part to the core: it becomes hard, stable and reaches its final properties.
Finish by removing supports (resin uses a lot of them) and, if needed, sanding/finishing. "Wash & cure" stations (Elegoo Mercury, Anycubic Wash & Cure…) combine washing and curing.
Too little curing = a fragile part that's still toxic on the surface. Too much curing = a brittle, yellowed part. It's a balance to dial in per resin.
Dangers & safety
This is the most important — and most neglected — point. Uncured liquid resin is toxic. Take it seriously:
- Skin contact: resin is irritating and sensitizing. Repeated exposure can trigger a cumulative allergy (sometimes permanent). Nitrile gloves every time — never bare hands.
- VOCs / fumes: resin and IPA give off volatile organic compounds. Effective ventilation is essential — an aired room, extraction to the outside, and ideally a respirator with organic-vapor cartridges (A1/A2 type). Never print in a closed living space. ⚠️ Smell is not a good gauge: some VOCs barely smell yet remain harmful.
- UV: don't stare at the source and protect your eyes; cure light is intense.
- Eyes: safety glasses when handling (splashes).
Never pour liquid resin, used IPA or soaked paper towels down the sink or into the trash. Cure under UV / sunlight any liquid residue: once solid, resin becomes an inert plastic you can throw away. Dirty IPA is handled as chemical waste.
Minimum PPE: nitrile gloves, glasses, VOC respirator, protected work surface, ventilation. Keep resin and IPA away from light and out of reach of children and pets; IPA is flammable.
Pros & cons
Pros
- Extreme detail: unmatched fineness — figurines, miniatures, jewelry, dental, precise prototypes.
- Smooth surface: no visible layer lines like FDM.
- "Free" plate: filling the plate costs almost no extra time.
- No nozzle/flow tuning: fewer mechanical variables than FDM.
Cons
- Toxicity & safety: PPE, ventilation, waste handling — non-negotiable.
- Mandatory post-processing: wash + cure = time and consumables every print.
- Limited volume: small parts mostly; large formats stay expensive.
- Brittleness: standard resins are brittle (tough/ABS-like resins help, without matching technical FDM).
- Messy & maintenance: vat, FEP film to replace, resin everywhere if you're not methodical.
The real cost
The printer's price is only part of the story. The full budget:
| Printer (entry/mid) | ≈ $150 – 400 (Mars 5 ≈ $250, Saturn 4 Ultra ≈ $380) |
| Printer (large format) | ≈ $600 – 1,000+ (Anycubic M7 Max, Phrozen Mega) |
| Resin | ≈ $20 – 40/L (standard) · more for tough, ABS-like, water-washable, castable |
| Wash & cure station | ≈ $100 – 150 |
| Recurring consumables | IPA, nitrile gloves, FEP/nFEP films (≈ $10–15, replaced periodically), filters, paper |
| Safety | Respirator ≈ $30 – 50 · ventilation/extraction |
| Hidden costs | Post-processing time · waste handling |
A serious setup (mid-range printer + wash & cure + safety gear + first resin) therefore lands closer to $500–600 than the $250 on the box.
The brands
The consumer market is dominated by three players, plus Creality.
- Elegoo — the leader. The Mars line (small format, ideal for minis: Mars 5 / Mars 5 Ultra ≈ $250–260) and the Saturn line (mid/large format: Saturn 4 Ultra 12K/16K ≈ $380). Excellent value, mature ecosystem — see our Elegoo resin guide.
- Anycubic — the Photon Mono M7 line (14K ≈ $350), M7 Pro and M7 Max (large format, rugged ≈ $900), plus the Mono 4 (budget) and the P1 (dual-material). See our Anycubic Photon guide.
- Phrozen — quality and community: Sonic Mini 8K S (≈ $329, a miniatures benchmark), Sonic Mighty 14K Revo (high detail) and Sonic Mega 8K S (very large format). See our Phrozen guide.
- Creality — the Halot line (see our Halot-X1 guide).
On software, two resin slicers dominate: Chitubox and Lychee Slicer (support generation, hollowing, drain holes).
Who's it for?
Resin is for you if you're after detail: figurines and modeling, jewelry, dental/medical, precise prototypes — and if you accept the safety discipline and post-processing. For functional, large or rugged parts, FDM stays simpler and safer. Many makers end up with both: an FDM for utility, a resin for fineness. For a concrete machine, see the Creality Halot-X1.
Detail is king, as long as you respect gloves, respirator, ventilation and post-processing. Resin rewards method, not improvisation.