3D-Printed Sacrificial & Casting Cores
Rigid cores that come out clean — break-out, dissolve, or burn-out — for latex dip molding, resin and metal casting, and hollow mold work. Smooth SLA resin surface, per-part materials, priced the moment you upload.
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Latex & silicone dip molding
A rigid core you dip-coat, then break or dissolve out from the inside to leave a hollow, flexible part. Common for masks, props, anatomical and medical models.
Resin & plaster casting
Sacrificial cores and masters for hollow resin pours, mother molds, and one-off plaster work where the core has to disappear after curing.
Lost-core & hollow castings
Cores that define internal channels and cavities, then break away once the surrounding material has set.
Pattern & mold masters
Smooth, dimensionally accurate masters for silicone molds and small-run casting — printed in high-detail resin.
Pick how the core comes out — we print it to match
A sacrificial core only works if you can get it out of the finished part. The right approach depends on your process, so tell us how you plan to remove it and we’ll print accordingly:
- Break-out (most common): a brittle, high-detail resin printed hollow with a thin internal lattice and a drain/access opening. It holds its shape through molding, then cracks and clears out cleanly — the smooth-surface equivalent of a gypsum/ProJet core, and we can iterate wall thickness with you fast since we print it in-house.
- Dissolve-out: a water-soluble PVA core (FDM) that rinses away in warm water and leaves cured latex, silicone, or resin untouched. Slightly less surface detail than resin, but nothing to break.
- Burn-out: castable resin for lost-wax/lost-resin investment work where the core is melted or burned away. Best where your process actually reaches burnout temperature.
One question settles most of it: do you need actual gypsum/sandstone, or just a core that behaves like it — rigid going in, gone coming out? If it’s the behavior, a brittle resin core gets you there with a better finish and a faster turnaround. If you genuinely need binder-jet gypsum, we can source it for you too.
Send a STEP, STL, OBJ, or 3MF and you’ll see a live preview and price instantly — or upload several cores at once and configure each one separately. New to this? Send one representative core and we’ll print it a couple of ways so you can test which releases best before committing to a batch. Every core is checked by a real person before it goes on a printer.
Helpful guides
Casting core FAQ
How do I get the core out of the finished part?
Three ways, depending on your process: break-out (a brittle resin core printed hollow so it crushes and clears through an opening), dissolve-out (a water-soluble PVA core that rinses away in warm water), or burn-out (castable resin for investment casting). Tell us your method and we print to match.
Resin or filament for a sacrificial core?
For a smooth surface and clean break-out, a brittle SLA resin printed hollow is usually best. For dissolve-out cores, water-soluble PVA filament is the move. We recommend the right one based on how you remove it.
Can you do dissolvable cores?
Yes — water-soluble PVA cores dissolve in warm water and leave cured latex, silicone, or resin alone. Note that cured SLA resin does not dissolve, so resin is the break-out path and PVA is the dissolve path.
Do you do real gypsum / binder-jet (ProJet 660-style) cores?
Our in-house lane is smooth break-out resin and dissolvable PVA, which match the behavior most people actually want. If you specifically need binder-jet gypsum, we can source it for you — just ask.
What files do you accept, and is the quote instant?
STEP, STL, OBJ, 3MF, PLY, and GLTF/GLB all preview and price instantly in the browser — including solid STEP CAD. Upload one core or several at once and configure each.
How much does a core cost?
Most small cores start around $12, priced by the grams the part actually uses (you choose the infill). You see the exact price the moment you upload. Larger or multi-core jobs are quoted the same way, instantly.
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