Resin (SLA/MSLA) vs FDM

How FDM Works

FDM (also called FFF — Fused Filament Fabrication) works by melting a thermoplastic filament and extruding it through a heated nozzle. The nozzle moves along X and Y axes, depositing material line by line to form a layer. Once a layer is complete, the print bed (or the nozzle) moves down (or up) by one layer height, and the process repeats.

The filament is typically a 1.75 mm diameter spool of plastic — PLA, PETG, ABS, TPU, nylon, and many more. The nozzle temperature, print speed, and cooling all determine the quality of the final print. Because the nozzle traces each line individually, print time depends heavily on the geometry and size of the object.

Think of it as: a very precise hot-glue gun on a robotic arm, drawing your object one layer at a time.

How Resin Printing Works

Resin printing (MSLA) works by curing liquid photopolymer resin with UV light. The printer has a vat filled with liquid resin and an LCD screen at the bottom. For each layer, the LCD displays a mask — the cross-section of the object — while a UV LED array shines through it. Wherever light passes through the LCD, the resin hardens. The build plate then lifts slightly, fresh resin flows underneath, and the next layer is cured.

Because an entire layer is cured at once (rather than traced line by line), the print time depends only on the height of the object, not its horizontal footprint. You can print one miniature or twenty in the same amount of time, as long as they fit on the build plate.

Think of it as: a UV projector hardening a photograph into plastic, one slice at a time, from the bottom up.

Print Quality & Detail

Resin wins decisively for fine detail. MSLA printers have an XY resolution determined by the LCD pixel size — typically 30-50 microns. Combined with layer heights as low as 10-20 microns, resin printers can reproduce incredibly fine surface detail: scales on a dragon miniature, tiny text, filigree jewelry patterns.

FDM, by contrast, is limited by nozzle diameter (typically 0.4 mm) and layer height (typically 0.12-0.28 mm). The result is visible layer lines and a slightly rough surface. For many functional parts, this is perfectly adequate — but for display miniatures, jewelry masters, or dental models, FDM simply cannot match resin.

Build Volume

FDM typically offers much larger build volumes. Entry-level FDM printers like the Bambu Lab A1 or Prusa MK4 offer roughly 250 x 250 x 250 mm of build space. Larger machines (Ender 5 Plus, CR-10 series) go up to 400+ mm in each dimension.

Resin printers have traditionally been smaller, but the gap is closing. The Elegoo Saturn 3 (218 x 123 x 250 mm) and Elegoo Mars 5 Ultra offer respectable volumes. Large-format resin printers exist but are expensive and consume vast amounts of resin per print.

If you regularly print large enclosures, furniture parts, or full-size helmets, FDM remains the practical choice.

Material Variety

FDM has a much wider range of functional materials. You can print in PLA, PETG, ABS, ASA, TPU (flexible), nylon, polycarbonate, carbon-fiber composites, and even metal-fill or wood-fill filaments. This diversity means you can choose a material specifically suited to your part's mechanical, thermal, or chemical requirements.

Resin material options are more limited but growing rapidly. Standard resin is brittle, but specialty resins now include tough/ABS-like (for functional parts), flexible (rubber-like), castable/burnout (for jewelry lost-wax casting), dental-certified, and high-temperature formulations. However, no resin can match the mechanical toughness of engineering FDM filaments like nylon or polycarbonate.

Strength & Durability

FDM parts are generally stronger for functional use. A well-printed PETG or ABS part can withstand significant mechanical loads, making FDM ideal for brackets, jigs, tool holders, and mechanical enclosures. The layer adhesion in FDM is good (especially with the right temperature and cooling settings), and the material itself is inherently ductile — it bends before it breaks.

Standard resin parts tend to be brittle. They look fantastic but can shatter on impact rather than flex. Tough resins improve on this considerably but still lag behind engineering FDM filaments. Resin parts can also degrade with prolonged UV exposure if not properly post-cured or coated.

If your part needs to bear load, resist impact, or survive outdoor use, FDM with PETG, ASA, or nylon is the safer bet.

Post-Processing

FDM post-processing is simple: remove supports (snap or cut them off), optionally sand, and you are done. Some users go further with vapor smoothing (for ABS) or filler/primer for cosmetic parts, but it is not required.

Resin post-processing is mandatory and more involved:

• Washing: prints must be rinsed in isopropyl alcohol (IPA) or a water-washable solution to remove uncured resin. This requires a wash station or at least a container and some agitation.
• UV curing: after washing, prints must be exposed to UV light (a curing station or sunlight) to fully harden. Undercured prints remain soft and may warp.
• Support removal: resin supports are thin and numerous — removing them carefully is important to avoid scarring the surface.

Budget an extra 15-30 minutes per print for resin post-processing, plus the cost of IPA and a wash/cure station. For the full workflow (and safety), see our resin process guide.

Safety & Health

This is the single biggest practical difference between the two technologies.

Resin is toxic. Uncured resin is a skin sensitizer and irritant. Direct skin contact can cause allergic reactions (some people develop permanent sensitivity). The fumes are unpleasant and potentially harmful with prolonged exposure. You must wear nitrile gloves at all times when handling resin or uncured prints, work in a well-ventilated area (ideally with a fume extractor or in a garage), and dispose of waste resin and IPA responsibly — they cannot go down the drain.

FDM is far safer. PLA is non-toxic and nearly odorless. PETG produces minimal fumes. ABS and ASA do emit volatile organic compounds (VOCs) and should be printed in an enclosed printer with ventilation, but even then the risk is much lower than handling liquid resin. FDM is suitable for living spaces, offices, and schools with basic precautions.

Cost Comparison

Entry-level prices for both technologies have converged. You can get a capable FDM printer or a resin printer for roughly 200-400 EUR. However, the ongoing costs differ significantly.

FDM is cheaper to operate long-term. The total cost of ownership for resin is higher once you factor in consumables, cleaning supplies, and replacement films.

Print Speed

Modern resin printers are remarkably fast. Because an entire layer cures at once, printing a full build plate of miniatures takes the same time as printing a single one. A typical resin print might take 2-4 hours regardless of how many objects are on the plate.

FDM has been catching up with high-speed printers like the Bambu Lab P1S and X1C, which can print at 200-500 mm/s with input shaping. But FDM speed still depends on part geometry — a tall, narrow part prints roughly as fast as on resin, but a plate full of many small objects will be much slower on FDM because the nozzle must trace each one individually.

Rule of thumb: for batch production of small parts, resin is faster. For a single large part, modern high-speed FDM is competitive or faster.

Smell & Workspace Requirements

Resin smells. A lot. Even "low-odor" resins have a noticeable chemical smell that most people find unpleasant. The printer itself, the resin vat, the wash station, and drying prints all emit fumes. A resin printer ideally needs a dedicated space — a garage, a well-ventilated workshop, or at minimum a room with an exhaust fan that you can close off from your living area.

FDM printers are mostly odorless. PLA and PETG have virtually no smell. ABS and ASA have a noticeable plastic odor and should be printed in an enclosed space. But in general, an FDM printer can live on your desk, in your office, or in a shared room without causing discomfort.

Also consider the mess factor: resin printing involves liquid resin, IPA baths, dripping prints, and occasional spills. FDM is a dry process — the worst mess is the occasional support or brim you trim off.

Best Technology For...

Can You Have Both?

Yes — and many enthusiasts do. The technologies are complementary, not competing. A common setup is an FDM printer for everyday functional printing and prototyping, paired with a resin printer for detailed miniatures, jewelry, or precision parts.

With entry-level printers for both technologies available at 200-300 EUR each, a dual setup is within reach for most hobbyists. Just make sure you have the workspace for the resin printer (ventilation, cleaning area) before committing.

Many tabletop gamers, for example, print terrain and large set pieces on FDM, then print character miniatures and fine props on resin — the best of both worlds.

Popular Models 2025-2026

FDM Printers

• Bambu Lab H2D — The 2025 flagship: enclosed CoreXY with a dual-nozzle toolhead and large format. Handles everything from PLA to engineering filaments.
• Bambu Lab P1S / A1 — The mainstream pair: the enclosed P1S is the workhorse for ABS/ASA/nylon, while the open A1 is the beginner-friendly all-rounder.
• Creality K2 Plus — Large 350 mm CoreXY with the CFS multi-color system and high-speed printing — Creality's direct answer to Bambu Lab.
• Prusa CORE One — Enclosed CoreXY, open-source, excellent for ABS/ASA/PC with superb community support.

Resin Printers

• Elegoo Saturn 4 Ultra (16K) — Large build volume and 16K resolution. The go-to for batch-printing miniatures.
• Elegoo Mars 5 Ultra — Compact, high-resolution, affordable. A perfect first resin printer.
• Anycubic Photon Mono M7 Pro / M7 Max — Fast and high-resolution, with the M7 Max offering large-format printing.
• Phrozen Arco / Sonic Mini 8K S — The Arco automates washing and curing; the Sonic Mini 8K S delivers ultra-fine detail for jewelry and dental work.