Resin or filament: which 3D printer should you buy?

One thing up front, so you know what you’re reading. The resin printer in this house is an Anycubic Photon M3 Premium, it’s my dad’s, and I’ve printed on it and spent a long time working out how to live with one. I don’t own a filament printer. So the resin half of this is first-hand, and on the filament half I’ve stuck to things I can show you the source for. That’s also why every price below comes from one shop on one day.

What do the two machines actually do?

A filament printer melts a plastic string and draws your part with it, one thin line at a time, through a metal tip called a nozzle. The nozzle is almost always 0.4mm across, and nearly everything about the machine follows from that. It can’t draw a line finer than its nozzle, it has to trace every part of every layer, and ten copies on the bed take about ten times as long as one.

A resin printer works the other way round. There’s an open tank of liquid resin with a screen in the bottom of it, like a phone screen. The screen blacks out everything except the shape of the current layer, a UV light shines up through it, and the resin that got hit by the light hardens. The plate the model hangs from lifts a fraction of a millimetre, and it flashes again.

That gives resin an advantage nobody mentions first: a print takes as long as the model is tall, no matter how much is on the plate. One miniature and a plate packed with forty of them finish at the same time, because the whole layer hardens in one flash whatever shape it is. If you want an army of something, that’s the argument all by itself.

Which one gives you finer detail?

Resin, and it’s not an argument.

The screen in dad’s printer has pixels 28.5 microns across. A micron is a thousandth of a millimetre, so that’s 0.0285mm. A filament printer’s 0.4mm nozzle is 400 microns. It’s the difference between a sharp pencil and a marker pen, and no amount of slowing the filament printer down changes the width of its nozzle.

One catch, because the adverts lean on that number hard. Pixel size isn’t the same as accuracy. The UV light spreads sideways a little into resin that was supposed to stay liquid, so parts come out a touch fatter than the file, and how much depends on how long each layer is exposed. Resin still wins on fine detail by miles. It just isn’t accurate to 28 microns.

What do they cost?

Everything here is Elegoo’s UK store on 13 October 2026, read off the product pages themselves. One shop, one day, so there’s nothing cherry-picked in it. Prices move, so check the date at the top of this page before you trust them.

The printers overlap completely in price. Cheapest first:

• Neptune 3 Pro, filament: £127, down from £240.99
• Mars 5, resin: £154, down from £200
• Neptune 4, filament: £169, down from £214
• Mars 5 Ultra, resin: £231, down from £285
• Centauri 2, filament: £239, down from £249

The cheapest machine on that list is a filament printer and so is the dearest, with the two resin printers sitting in between. Price can’t pick for you, which is most of why the rest of this page is about everything else. A Mars 5 at £154 undercutting two of the three filament printers is still how people end up with a resin one without having thought about the rest of it.

Worth knowing how those numbers are built, though. Nearly everything in that shop is discounted against a higher list price, and the discounts aren’t remotely comparable: the Neptune 3 Pro is 47% off and the Centauri 2 is 4% off. So read the left-hand number and ignore the saving. The Neptune 3 Pro is also an older model being cleared, which is exactly the kind of price that’s gone next month, so the date above matters more here than anywhere else on the page.

The material is close too. PLA, the standard beginner filament, is £11.99 a kilo. Standard resin is £14.99.

Then the resin list keeps going, and this is the real difference.

• A wash and cure machine, £120. It rinses the print and then hardens it off under UV. You can do both by hand in tubs and plenty of people do, but it’s a job either way.
• Isopropyl alcohol, sold as IPA, about £20 for five litres. It’s what washes the sticky resin off a finished print, and you get through it.
• Gloves, goggles, kitchen roll, and a sealed box to keep the resin in.
• Replacement film, £24 to £48 for five depending on the machine. A clear sheet sits in the bottom of the resin tank and the light shines up through it. It’s called FEP on older printers and PFA or ACF on newer ones. It gradually clouds over and eventually tears, so it’s a part you replace.
• A replacement screen. The screen under the tank sits in UV light all day and wears out, so it counts as a consumable: £111.99 for a Saturn 4, £197.99 for a Jupiter 2.

That last one is worth sitting with. A Saturn 4 is £267 and its screen is £111.99, so the part that wears out is getting on for half of what the machine cost. Ours is an older one and its screen has clearly dimmed, because dad runs each layer under the light for 10 seconds where the software’s default for that resin is 2.5. Nothing’s broken. It just needs four times the light it used to.

Filament’s equivalent list is a new nozzle when you wreck one, about £20 for a set, and a new build plate every long while.

What’s resin actually like to handle?

This is the part that isn’t on the box, and it’s the real decision.

A resin print comes out of the machine coated in liquid resin, and liquid resin is a labelled hazardous substance rather than a mild annoyance. This is the formal classification, not a cautious reading of it:

• It causes skin irritation and serious eye irritation
• It causes allergic skin reactions, which is the one that matters, below
• It irritates the respiratory system
• It’s harmful to aquatic life, with long lasting effects
• It’s for outdoors or a well-ventilated area only, and it’s stored locked up

The allergy one works differently from the rest, so it’s worth understanding properly. Irritation happens while the stuff is on your skin and then stops. An allergic reaction of this kind is your immune system learning the chemical, and once it has, it reacts worse every time rather than settling down. People don’t give up resin printing because it stung them once. They give up because two years in, their hands react to a single drop.

There’s a gap in that, worth knowing about before you commit. No glove material is rated to hold resin out, and no manufacturer will tell you how long a glove lasts in it. You’re told to wear chemically resistant gloves and left to work out which ones those are. The answer is nitrile, changed often, which works because you throw them away rather than because they hold.

Filament isn’t fume-free either, and I’m not going to pretend otherwise. Melting plastic gives off very fine particles and vapours. PLA is the lowest of the common materials and ABS and nylon are worse, but none of them are nothing, and opening a window doesn’t fix it. Measured in a real office, normal room ventilation on its own didn’t hold the particle count down while the printers ran. A fan venting outside, or an enclosed printer with a filter, did. So give a filament printer air as well. The difference is that filament’s problem is the air while it prints, and resin’s problem is a liquid you handle on every single print, plus the air.

Where does the waste go?

Straight to the point: uncured resin can’t go in the bin, and it can’t go down the sink. The resin and its container are hazardous waste, formally, and that’s how they have to be thrown out.

That covers more than the bottle. The IPA you washed prints in is now resin dissolved in alcohol. Failed prints are still wet. So is the paper towel. Water-washable resin doesn’t get you out of it, it just moves the problem into water that has resin in it.

What you do instead is harden the waste before you get rid of it. Leave the dirty wash liquid in a clear tub in the sun or under a UV lamp until the resin in it sets into a solid lump, and then the lump is ordinary plastic that can go in the bin. The leftover liquid and the empty bottles go to a council waste site that takes chemicals. The rule is that nothing leaves the bench while it’s still liquid, and there’s a full routine for it in resin print post-processing.

One safety note while you’re doing that. IPA’s flash point is about 12°C, which means at normal UK room temperature it’s already giving off vapour that will catch light. It wants a lid, and it wants to be nowhere near anything hot.

Filament’s waste is a bag of failed prints and snipped-off bits, and it goes in the bin.

Which one is stronger?

Neither, cleanly, and the reason is interesting.

A filament part is lines of plastic welded to each other, and the weld between two layers is never quite as good as the plastic itself. So it’s strong along the layers and weaker across them, and when it breaks it splits along one of those joins. You work around that by turning the part so the force runs along the layers rather than across them, which is a real skill and worth having.

A resin part has no layers in that sense. It sets as one solid piece, so it’s equally strong in every direction, which sounds better and mostly isn’t, because standard resin is brittle. It holds a load right up until it snaps, with no bend to warn you. Tougher resins trade some detail back for some give.

Two more resin things that catch people out. Hardened resin keeps reacting to UV light, so a part left on a sunny windowsill goes yellow and gets more brittle over months. And brittle changes how a part finishes: on PLA a deburring tool peels one long curl off an edge, where on resin you get dust and little chips instead. Same tool, same stroke, completely different feel, and it’s not a sign you’re doing it wrong.

So which should you get?

Filament if you want to print things that have a job. Brackets, organisers, replacement knobs, boxes, parts for other projects. You want to walk up to the machine, take the part off and use it. You’re printing in a bedroom, a shared flat, or anywhere a ventilated bench and a locked box aren’t realistic. Or you don’t know yet what you’ll print, which is almost everyone at the start.

Resin if what you want to print is small and finely detailed and you already know it is. Miniatures, busts, scale models, jewellery patterns, anything where a 0.4mm line is simply too fat. You’ve got somewhere ventilated that isn’t where you sleep, you can keep a labelled chemical locked away, and you’re genuinely fine with gloves, a wash and a cure being part of every print.

Neither yet if price is what’s deciding it. The cheapest box on that list is a filament printer anyway, and on the resin side the box was never the expensive part. Picking on the sticker is the one wrong reason, and it’s the most common one.

What you need next to each

For resin: nitrile gloves, goggles, something to wash prints in, a way to cure them, a scraper, and somewhere sealed to keep the bottle. Tools come after that.

For filament: flush cutters, which are snips with one flat jaw so they cut level with a surface, one flat needle file, and something abrasive. That finishes almost any print. There’s more on that in what tools you need for 3D printing, and on getting the supports off without wrecking the surface underneath in removing supports without marks.

Full disclosure: I sell a finishing kit with the cutters, files and sanding sponges in it. It’s aimed at filament prints, it works fine on resin, and it isn’t what you buy first if you’ve just ordered a resin printer. Gloves are.