Alcohol Ink Petri Dish Pour
SaveThe petri dish technique creates extraordinary blooming patterns using nothing more than drops of alcohol ink and a single drop of isopropyl alcohol in wet resin.
Step-by-Step Instructions
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Step 1
Set up your workspace with coaster molds on a flat, level surface and wear nitrile gloves. The petri dish technique produces a lot of ink splatter, so protect your work surface generously. Have your alcohol inks, a small dropper bottle of isopropyl alcohol (91% or higher works best), and the heat gun ready before you begin mixing.
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Step 2
Mix a small batch of resin — about 100–150 ml is sufficient for four to six coasters — at a 1:1 ratio, stirring thoroughly for three minutes. Allow to rest for two minutes. Pour a thin base layer into each round coaster mold — about half full — and pass the heat gun briefly over each mold to pop any surface bubbles.
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Step 3
Working on one coaster at a time, drop two to four colours of alcohol ink directly onto the resin surface in the centre of the mold. Add colours one at a time — a dark base colour first, then jewel-bright accents on top. Each drop will spread slightly on contact with the liquid resin.
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Step 4
Now add a single drop of isopropyl alcohol to the centre of the ink cluster. Watch as the alcohol displaces the ink outward in a dramatic blooming ring pattern — this is the defining moment of the petri dish technique and it is genuinely spectacular every time. The inks push outward in concentric rings of colour, creating complex patterns that look like microscopic organisms under a lens.
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Step 5
Repeat the isopropyl alcohol drop technique two or three more times over the next few minutes as the resin begins to thicken slightly. Each subsequent drop produces a new set of bloom rings layered over the previous ones, creating the characteristic petri dish depth and complexity. Do not over-add — two to four drops total per coaster is usually sufficient.
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Step 6
Pop any surface bubbles with a final brief heat gun pass. Cover the molds and leave to cure for 24 hours completely undisturbed. The bloom patterns will remain exactly as you left them, locked in place as the resin cures to a glossy, crystal-clear finish.
What You'll Need
ArtResin Epoxy Resin 32 oz Kit
PickA small amount goes a long way in coaster-sized molds — one kit makes many petri dish pours.
From $54.99
Shop on AmazonTim Holtz Ranger Alcohol Ink 9-Colour Set
PickThe inks bloom into stunning rings when displaced by isopropyl alcohol drops — choose 3–4 complementary tones.
From $28.99
Shop on AmazonSilicone Coaster Molds — Round (6-pack)
Round coaster molds are the classic petri dish format — the circular shape shows off the bloom rings perfectly.
From $12.99
Shop on AmazonMini Heat Gun 300 W
PickFor popping surface bubbles before the bloom technique begins.
From $15.99
Shop on AmazonAffiliate Disclosure: Supply links go straight to Amazon — you pay the exact same price either way. I earn a small commission that keeps every tutorial on this site free.
Common Questions
- Do I need to wear gloves when working with resin?
- Yes — nitrile gloves are non-negotiable for every resin session. Liquid epoxy resin is a skin sensitiser; repeated skin contact can cause an allergic reaction that worsens with each exposure. Gloves also keep fingerprints off molds and prevent resin from sticking to your hands.
- Why does my resin cure cloudy or tacky?
- Cloudiness almost always means undermixing — the resin and hardener were not combined thoroughly enough. Tackiness means the same. Always stir for a full three minutes, scraping the sides and bottom of the cup, and allow the cup to rest two minutes before pouring.
- How do I get rid of bubbles in resin?
- A brief pass with a mini heat gun or kitchen torch — two to three seconds at about 15 cm distance — pops surface bubbles. Do not hold the heat source too close or too long, as overheating can scorch the surface or cause the resin to boil.
- How long does resin take to cure?
- Most art resins (including ArtResin) are fully demolded after 24 hours for small pieces like coasters and bookmarks. Larger pours like serving trays need 48 hours. Full hardness — maximum scratch resistance — is reached after 72 hours in all cases.
- Can I add alcohol ink to any epoxy resin?
- Yes — alcohol inks work with any clear epoxy resin. Add them after pouring into the mold rather than mixing into the cup, as this gives you more control over colour placement and bloom patterns.
