The real question is not which resin is “better” - it is which one fits your project’s size, depth, and finish. Here is the 30-second answer: thin, fast, and tiny means UV resin; thick, durable, and food-contact means epoxy. UV resin cures in 1-8 minutes per layer under a 36W+ UV lamp, needs no mixing, and wastes almost nothing - which makes it the right tool for jewelry, pendants, bezels, miniatures, and keychains that fit under a lamp in a shape under about 1/4 inch deep (roughly under 8cm overall). Two-part epoxy cures by chemical reaction over 24-72 hours with no lamp at all, self-levels into a glassy surface, and goes deeper and more durably - which makes it the right tool for coasters, cutting boards, art panels, river tables, and tabletop art. The comparison table below splits the three families - single-part UV resin, art-coat epoxy, and deep-pour epoxy - against the numbers that actually decide the job: cure time, pour depth, hardness, food safety, and cost per gram.
The honest rule before you read another spec
Most “UV resin vs epoxy” arguments treat it like a winner-takes-all fight. It is not. The two cure by opposite physics and live in opposite project sizes, so the comparison is really a routing decision. If your piece is small, shallow, and you want it solid in minutes, UV resin wins on speed and zero waste. If your piece is deep, large, needs to survive a hot coffee mug, or has to touch food, epoxy wins on depth, durability, and certified safety. The trap beginners fall into is buying one resin and forcing it to do the other resin’s job - pouring UV resin 1/2 inch deep (the bottom never cures), or trying to coat a tiny bezel in slow 72-hour epoxy and wasting most of a mixed batch. Match the resin to the project first, and the rest of this page just confirms your pick.
How each one cures: photopolymer in minutes vs chemistry in hours
UV resin is a single-component photopolymer. It contains a photoinitiator that does nothing until it sees ultraviolet light in the 365-405nm range. Shine a 36W+ UV/LED lamp (or strong direct sunlight) on it and it hardens in 1-8 minutes depending on layer thickness. Until that moment, it stays liquid in the bottle indefinitely - there is no pot life ticking down, no rush. The Let’s Resin Hard Type cures to roughly 85D Shore hardness with under 2% shrinkage at about 2000 cps viscosity, which is firm enough for pendants and bezels that take daily knocks.
Two-part epoxy is the opposite. You mix resin and hardener in a fixed ratio - 1:1 by volume for ArtResin, 2A:1B by volume for Let’s Resin Deep Pour - and a chemical reaction kicks off the moment they meet. No lamp, no light: the reaction runs on its own and generates its own heat (the exotherm). That reaction takes hours, not minutes, which is why epoxy gives you a long, relaxed working window but a slow cure. Get the ratio wrong and the resin never fully hardens - the classic sticky, soft, never-curing failure. If you hit that, our guide on resin working, cure, and demold times walks through what each stage should feel like and when something has gone wrong.
Working time and cure time compared
This is the single biggest practical difference, and it cuts both ways.
UV resin gives you indefinite working time - it will not cure until you expose it to UV - then cures in minutes. That is perfect for layer-by-layer detail work: place an inclusion, flash-cure for two minutes, add the next layer, cure again. You are never racing a clock.
Epoxy flips that. ArtResin gives about 45 minutes of working time to mix colorants and pour without rushing, then needs 24 hours to dry to touch and 72 hours for full cure at a 1/8-inch layer. Deep-pour epoxy stretches the working window to up to 80 minutes for big pours, with roughly 8 hours to demold and 48-72 hours to full cure. So epoxy buys you a generous pour window but costs you days before the piece is finished. If you need ten finished keychains tonight, UV resin does it; if you need one perfect coaster by the weekend, epoxy is fine.
Depth and size limits: the ceiling nobody warns beginners about
This is where UV resin’s limits bite hardest. UV light only penetrates so far. Push past roughly 1/4 inch of depth, or an object much larger than about 8cm, and the light cannot reach the bottom - the surface skins over while the core stays gooey. Opaque pigments make it worse, because they block the light from passing through at all. So UV resin is genuinely capped at thin, shallow, fairly translucent pieces.
Epoxy has its own depth rule, but a different one. ArtResin and other art-coat epoxies max out at 1/8 inch (3mm) per pour - not because of light, but because thicker layers trap bubbles and build up too much exothermic heat. You can build depth by pouring multiple stacked layers, but each needs time to set first. When you need real depth in a single pour, you switch tools entirely: deep-pour epoxy pours 2-4 inches at once because its slow, low-exotherm chemistry handles the thick mass without cracking or overheating. That is the resin for river tables, deep castings, and flower preservation - see our best deep-pour epoxy for river tables roundup for the specific products that hit those depths reliably.
So the depth ladder is simple: under 1/4 inch and small, UV resin; thin coats and surfaces, art-coat epoxy; anything over 1/4 inch in one shot, deep-pour epoxy.
Durability, hardness, and yellowing over time
Both cure to genuinely hard, usable surfaces - UV resin around 85D Shore, epoxy hard and scratch-resistant - so for everyday handling either holds up. The real long-term difference is yellowing. UV resin yellows faster. That is partly its chemistry and partly that small bottles are not always heavily UV-stabilized. Quality art epoxy like ArtResin is formulated with UV stabilizers specifically to resist yellowing, so a clear coaster or art panel stays clearer for longer. Interestingly, the wavelength matters too: curing UV resin at 365nm rather than only 405nm tends to reduce its yellowing. If a piece will sit in sunlight or you care about it staying water-clear for years, epoxy is the safer bet, and the comparison table below rates yellowing resistance “lower” for UV resin and “high” for both epoxies.
Food safety and toxicity: the part you cannot fudge
This is the most important section if you make anything that touches food or drink, and it is where the two resins are not equivalent.
UV resin is not food-safe. Standard formulas are not designed, tested, or certified for food contact, and they can leach small amounts of chemicals over time - more so with heat or acidic foods. Do not make a UV-resin cup, plate, or food-contact coaster surface.
ArtResin is food-contact safe once fully cured - it is ASTM-designated non-toxic when used as directed and third-party tested for leaching and migration. Two conditions matter: it has to be fully cured, and the contact surface has to be clear (adding colorant voids the food-safe status unless you seal it under a clear topcoat). Deep-pour epoxy, by contrast, is generally not marketed as food-safe, so do not assume a river-table resin is safe for a cutting board.
A word on toxicity while liquid: both uncured resins are skin, eye, and lung irritants and potential sensitizers - repeated skin contact can trigger an allergy that does not go away. UV resin is single-part and cures in minutes, so it shortens your exposure window and gives off fewer lingering fumes; epoxy’s amine hardeners can be more irritating and the cure releases fumes for hours. Either way: nitrile gloves and ventilation are non-negotiable, and for long sessions an organic-vapor respirator is the right call. The food-safety question goes much deeper than one paragraph - our food-safe epoxy FDA & CFR 21 guide covers what the certifications actually mean and which products carry them.
Cost per gram and cost per finished project
Per gram, UV resin is the more expensive material: roughly 4-10 cents per gram, sold in small 100-200g bottles. Epoxy runs roughly 2-5 cents per gram, sold in larger kits and bulk - deep-pour drops to around 2-4 cents/g in big sizes. ArtResin sits in the middle at roughly 4-7 cents/g because it is a premium art-coat epoxy in smaller kits (an 8oz kit covers only about 2 sq ft).
But cost-per-gram is the wrong number for choosing. What matters is cost per finished piece. For a tiny pendant, UV resin uses a gram or two with near-zero waste - so even at a higher per-gram price it is cheap per piece, and you avoid the epoxy problem of mixing more than you need and binning the rest. For a coaster, panel, or river table, you are using tens or hundreds of grams, so epoxy’s lower per-gram price compounds into a far cheaper finished project. Small and detailed: UV resin’s waste advantage wins. Big and deep: epoxy’s bulk price wins.
Project-by-project pick
The fastest way to choose - match the work to the resin:
- Jewelry, pendants, earrings, bezels - UV resin. Cures in 2-5 minutes per layer, builds detail layer by layer, almost no waste.
- Miniatures and keychains - UV resin, as long as they are under ~1/4 inch / 8cm and not fully opaque.
- Coasters - art-coat epoxy (ArtResin). They are usually 1/4 inch or thicker, often touch drinks, and want a glassy clear top - all UV resin weaknesses, all epoxy strengths.
- Cutting boards and food-contact tops - food-safe cured ArtResin, clear contact surface only.
- Art panels and tabletop pours - art-coat epoxy for the self-leveling glass finish.
- River tables and deep castings - deep-pour epoxy, 2-4 inches in one pour.
- Flower and botanical preservation in depth - deep-pour epoxy for the slow, low-heat cure.
- A bit of everything - keep UV resin and one epoxy on the bench. Most serious crafters do.
Equipment you actually need for each
The resins demand different kit. UV resin needs a 36W+ UV/LED lamp at 365-405nm - the wattage and wavelength are not optional, since a weak lamp leaves you with tacky, under-cured pieces. A 36W LED lamp cures thin layers in about 2-4 minutes and thicker pours in 5-8 minutes; our best UV lamp for resin curing guide covers what wattage and wavelength to look for. Beyond the lamp you need very little - molds and a few tools.
Epoxy needs no lamp but more handling gear: graduated mixing cups, a scale or measuring cups for the exact ratio, stir sticks, and a heat gun or torch to pop surface bubbles after pouring. For deep pours you also want a way to manage the exotherm - pouring in a temperature-controlled room and respecting the 2-4 inch limit keeps the mass from overheating and cracking.
The verdict: which to buy, and why many crafters keep both
Buy UV resin if your work is thin, fast, and tiny - jewelry, bezels, miniatures, keychains under about 1/4 inch that cure in 2-8 minutes under a 36W+ lamp. You get speed, no mixing, indefinite working time, and almost no waste, at the cost of a higher per-gram price, faster yellowing, and no food safety.
Buy 2-part epoxy if your work is thick, durable, or food-contact - coasters, panels, cutting boards, and tabletop art. Art-coat epoxy like ArtResin gives ~45 minutes of working time, a 1/8-inch max per pour, dry-to-touch in 24h, full cure in 72h, and verified food-contact safety once cured and clear. For anything over ~1/4 inch in a single pour, skip both and use a dedicated deep-pour epoxy (2-4 inch capability, up to 80 min working time, 48-72h cure).
The honest endgame: most serious crafters keep both on the bench - UV resin for the fast small detail work and epoxy for the deep, durable, food-safe pieces - and route each project to the resin that was built for it.