Coasters are the perfect first resin project — flat, forgiving, and genuinely useful — yet the difference between a craft-fair reject and a boutique-worthy set comes down to a handful of details most tutorials skip. This guide covers the right mold and resin, how much to mix per coaster, the color techniques that actually look expensive, and the honest answer about hot mugs — plus the finishing touches that make a set feel bought, not made.
What do you need to make resin coasters?
You need four things: a silicone coaster mold, epoxy resin, colorants, and basic mixing tools. The mold matters most — a flexible silicone mold gives you a glossy face and clean release that rigid molds can't match.
- A silicone coaster mold — flexible, so the cured coaster pops out glossy and intact.
- Epoxy art resin — standard 1:1 or 2:1 craft epoxy; coasters are thin, so no deep-pour formula needed.
- Colorants — resin pigments, inks, or micas made for epoxy.
- Tools — measuring cups, stir sticks, gloves, a level surface, and a torch or heat gun for bubbles.
Round, square, hexagonal, and shaped designs all work — browse the range in our coaster molds collection, from minimalist circles to a themed skull coaster set.
Which resin should you use for coasters?
Use a standard art or coating epoxy at its labeled ratio — coasters are shallow pours, so you don't need deep-pour resin. A typical coaster is only 6–8 mm thick, well within a normal epoxy's safe pour depth. What matters more is measuring precisely and mixing thoroughly, because a thin flat piece shows every soft spot.
Measure by the exact method your resin specifies and mix for a full three minutes, scraping the cup's sides. If your casts ever come out bendy or tacky, the ratio is the usual culprit — our guide on resin mix ratios covers the numbers and fixes in detail.
How much resin do you need per coaster?
A standard 10 cm (4-inch) round coaster takes roughly 50–70 ml of mixed resin, depending on depth. The reliable way to know for sure: fill one mold cavity with water, pour it into a measuring cup, and note the volume — that's your per-coaster amount. Mix about 10% extra to cover what clings to the cup.
- Fill a cavity with water and measure the volume.
- Multiply by your coaster count and add ~10% margin.
- Dry the mold completely before pouring — water is resin's enemy.
How do you make resin coasters, step by step?
The process is a short sequence: mix, color, pour, de-bubble, cure, demold. Follow it in order and a clean set is very achievable on your first try.
- Level your surface. A tilted table means lopsided coasters — check with a spirit level.
- Measure and mix the resin at its exact ratio, stirring slowly for 3 minutes.
- Split into cups and color. One cup per color, plus a larger clear one.
- Pour your design — colors first, clear between, letting them meet and marble.
- Pop the bubbles. Pass a torch or heat gun quickly over the surface in sweeping motions.
- Cover and cure for 12–24 hours somewhere warm (21–24°C), dust-free, and undisturbed.
- Demold and finish. Flex the mold, peel the coaster free, and let it fully harden for 24–72 hours more.
What colors look best in resin coasters?
The combinations that consistently look boutique are simple: one or two colors plus plenty of clear or white. Restraint reads as expensive; a rainbow of every pigment you own reads as homemade. Three reliable palettes to start with:
| Palette | Colors | The look |
|---|---|---|
| Ocean / geode | Deep blue or teal + white + clear | Waves and agate rings; the classic bestseller |
| Marble | White + a whisper of black or gold | Quiet, high-end, matches any table |
| Smoke & gold | Translucent grey or amber + gold mica | Moody, luxe, great for gift sets |
The go-to pour technique: run your darkest color around the rim, clear in the center, then alternate inward — the rings blend into soft agate-like bands as they settle. Tilt gently or drag a stick through for marbling. A matching tray finishes the set beautifully — see our tray molds for companion pieces.
Are resin coasters heat resistant?
Only moderately — standard epoxy starts to soften around 50–60°C, so a fresh mug of boiling tea can leave a faint ring over time. That's the honest answer most tutorials dodge. Resin coasters handle warm drinks, iced drinks, and everyday use beautifully, but they're not trivets.
My first set taught me this: a straight-off-the-boil mug left a barely-visible matte ring on an otherwise glossy coaster. Since then I let the kettle sit a minute, and the sets I've made after have stayed flawless for years. If you sell your coasters, say "not for pans or boiling-hot mugs" on the care card — buyers respect the honesty.
How do you finish resin coasters so they feel professional?
Finishing is what separates handmade from boutique: sand the edges, back them with felt or rubber, and check the face for gloss. Ten extra minutes per set, and the difference is obvious the moment someone picks one up.
- Sand sharp edges lightly with 400–600 grit wet sandpaper, keeping the top face untouched.
- Add felt or rubber feet underneath so the coaster grips and never scratches a table.
- Buff fingerprints off the gloss with a microfiber cloth before gifting or photographing.
If a coaster comes out with a rough or dull face, the mold surface is usually to blame — a worn mold prints its wear onto every cast. Our guide on cleaning and caring for silicone molds keeps that glossy face glossy.
Why did my coaster come out bendy, tacky, or bubbly?
Thin flat pieces show mixing and curing flaws more than any other shape, and each flaw has a clear cause. Match the symptom to the fix.
| Problem | Cause | The fix |
|---|---|---|
| Bendy or flexible after demold | Demolded too early | Wait the full 24 hrs; it keeps hardening for days |
| Sticky or tacky surface | Ratio off or under-mixed | Measure exactly; mix 3 min, scraping the cup |
| Bubbles frozen in the face | Not torched after pouring | Warm the resin bottle first; torch in quick passes |
| Dust or hairs in the gloss | Cured uncovered | Cover with a box lid while curing |
| Uneven thickness | Table not level | Level the surface before pouring |
Frequently Asked Questions
What resin is best for coasters?
A standard art or coating epoxy at its labeled 1:1 or 2:1 ratio is ideal — coasters are shallow pours of about 6–8 mm, so deep-pour resin isn't needed. Precision matters more than the formula: measure exactly, mix a full three minutes, and cure warm. A well-mixed everyday epoxy makes a hard, glossy coaster.
Are resin coasters heat resistant?
Moderately. Standard epoxy softens around 50 to 60°C, so warm drinks are fine but a boiling-hot mug straight off the kettle can leave a faint mark over time. Treat resin coasters as coasters, not trivets, and let very hot drinks sit a minute first. Note this on a care card if you sell them.
How much resin do I need for one coaster?
A standard 10 cm round coaster takes roughly 50 to 70 ml of mixed resin. For an exact figure, fill one mold cavity with water and measure the volume — that's your per-coaster amount. Multiply by your coaster count, add about 10 percent for what clings to the cup, and dry the mold fully before pouring.
Why are my resin coasters bendy?
Bendy coasters were demolded too early or mixed off-ratio. Epoxy reaches a firm gel in 12 to 24 hours but keeps hardening for 24 to 72 hours more, so a fresh coaster that flexes usually just needs more time. If it stays soft after three days, the resin-to-hardener ratio was off and the cast won't fully recover.
How do you keep bubbles out of resin coasters?
Warm the resin bottles in warm water before mixing, stir slowly to avoid whipping in air, and pass a torch or heat gun over the poured surface in quick sweeps to pop what remains. Pouring in a thin stream close to the mold also helps. Flat coasters make bubbles easy to chase out compared with deep casts.
Ready to pour a set worth gifting? Browse shapes from minimalist rounds to statement designs in our coaster mold collection and make the coasters people flip over to inspect.
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