Short answer: a multi-cavity tray is a PETG plate with 9 identical hollows âor as many as you ask forâ where you pour tempered chocolate, water or gummy mix and get matching pieces without molding them one by one. On kingscutter.com you pick the figure and the size, then download the STL ready to print.
What is a multi-cavity tray and how is it generated?
A multi-cavity tray is a rigid one-piece mold with a grid of repeated cavities. Each cavity is a hollow shaped like the figure you chose, with the mouth facing up, so the liquid goes in from the top and the piece comes out from the top. The tray is the mold: there are no lids or loose parts to line up before pouring.
In the kingscutter.com designer the tray is parametric: you do not need a starting image. You pick the figure, the cavity size and how many rows and columns you want, and the site computes the whole block. If you prefer your own figure, you upload an STL, OBJ or 3MF file and the generator scales it so its longest side matches exactly the cavity size you asked for.
How the cavity is formed and why it always releases
The generator cuts the figure with a plane and keeps the lower half: that half is the cavity and the mouth sits on the cutting plane. The silhouette can only grow toward the mouth, so any undercut that would jam the piece is removed automatically. In practice, a figure with a neck âa gingerbread man, a bottle, a pointed heartâ releases as easily as a sphere.
The factory draft angle is 1.5° and it tilts the walls toward the mouth. It is the same principle as an industrial chocolate mold: the piece does not rub the wall on the way out.
What settings does the tray ship with?
The table below lists the values the kingscutter.com generator opens with. All of them can be changed before download, and the table is useful to decide the piece size before printing.
| Setting | Factory value | What it does |
|---|---|---|
| Cavities | 3 Ă 3 = 9 | Row and column grid; it can go down to 1 Ă 1 |
| Cavity size | 30 mm | Longest side of the figure inside the hollow |
| Cavity spacing | 6 mm | Wall left between one hollow and the next |
| Tray floor | 3 mm | Thickness under the cavity |
| Outer wall | 2.5 mm | Rim of the plate |
| Draft angle | 1.5° | Wall tilt toward the mouth |
| Headroom above the mouth | 10 mm | Air to pour without overflowing |
| Engine minimums | 1.2 mm | Spacing, floor and wall never go below that |
How much chocolate fits in a 30 mm cavity
A 30 mm cavity cut through the middle of the body leaves 15 mm of depth and about 7 cmÂł of volume. With 9 cavities, a full batch holds 63 cmÂł of chocolate, the amount of a small bar. According to our workshop measurement, that batch yields 9 wide-mouth bonbons, the right size to fill with ganache or hazelnut spread.
Rigid or flexible: which one should you pick?
The tray has 2 modes and they change the use completely. The rigid one prints the block with the cavities subtracted: that is the tray you pour chocolate or water into. The flexible one prints an open box with the figures as positives on the floor, so you pour silicone around them and pull out a soft mold.
- Rigid: a single piece, ready off the printer, no silicone and no curing.
- Flexible: it needs food-grade silicone and its curing time; it pays off when you want a mold that bends to release fine details.
If the goal is chocolate to sell, the rigid tray wins on cost and time. If you want a soft multi-cavity mold, the flexible mode and the custom silicone molds guide cover the same ground from another angle.
Does it work for ice?
Yes, and with one concrete advantage: the tray is open, so water has room to grow. When water freezes it expands in volume by about 9% (Wikipedia, Ice), and that expansion is why pipes burst and closed molds crack. In an open cavity the ice simply rises.
- Fill to 1 mm or 2 mm below the rim, not to the top: the ice needs that air.
- Let the tray rest 1 minute outside the freezer before unmolding.
- Do not knock the piece against the counter: at -18 °C PETG is less elastic and a corner can chip.
How do you unmold chocolate without marks?
The secret is not in the tray but in the tempering. Tempered chocolate crystallizes in the stable form, contracts as it cools and pulls away from the wall on its own. Badly tempered chocolate sticks, leaves a white haze and will not release.
The documented cycle has 4 steps: melt at 40 °C, cool to 32 °C to start crystallization, crystallize at 27 °C and come back to 29-31 °C before molding (Wikipedia, Chocolate tempering).
- Pour at 29-31 °C and tap the tray on the counter to release bubbles.
- Let it crystallize at a cool room temperature, between 18 °C and 20 °C, never in the fridge: sudden cold causes condensation and white fat bloom.
- When the gloss turns matte and the piece pulls away from the rim, flip the tray with a firm tap.
Which figures and finishes can you make?
The generator ships 3 base figures âcube, sphere and diamondâ and accepts any model of your own. The 30 mm sphere is the most requested size for bonbons; the diamond leaves a faceted face that shines with tempered chocolate; the cube is the one that stacks best for transport.
Beyond the figure, there are 3 settings that change the result:
- Popsicle stick slot of 10 Ă 2 mm: it turns the cavity into an ice pop mold. It is a new option, so test the first batch before going into production.
- Tray edge: the straight one stacks better and the rounded one leaves no corners to chip.
- Figure from your own drawing: the silhouette of an image you upload, with the same release rule.
For the holiday season, Christmas figures sell best: the kingscutter.com library has baubles and sparkles, a gingerbread house and Santa Claus ready to download.
Is it worth it for selling?
Yes, because the mold is printed once and the cavity repeats without a limit. According to Better Baker Club (2022), 37% of home bakers who sell their baking in the United States say cookies, brownies and bars are their best-selling items: molded chocolate follows the same logic of per-unit sales and seasonal gifting.
The math is simple: a 9-cavity tray prints in PETG in under 4 hours and is used dozens of times. According to our workshop measurement, a batch of 9 bonbons takes 12 minutes of active work between tempering, pouring and unmolding.
Which material is it printed in and how do you care for it?
The material is PETG, a filament suitable for food contact. Section 21 CFR 177.1315 of the eCFR (FDA) lists the PET polymers and copolymers authorized for food packaging, and the EFSA assesses those same materials for food contact in Europe.
- Wash by hand with warm water and soap, and dry before storing.
- No dishwasher and no hot water: heat warps the cavity and ruins the release.
- Do not pour hot caramel or boiling invert sugar; PETG does not reach those temperatures.
- Store it flat, cavities facing up, so the floor does not bend.
If you want to compare filaments, the PLA vs PETG guide explains why PLA is not for food contact.
Which plan do I need to download the tray?
The Chocolate and Ice Tray requires the Pro plan. The Cutter downloads free and without a limit; the other products on the free plan include 5 downloads per month, no card needed; and the Pro and Studio plans download without a limit. Credits do not pay for downloads: they buy designs from the Library and power the AI features, which cost 1 credit each.
How to start: 3 steps
- Open kingscutter.com/app/designer, pick Chocolate and Ice Tray and choose the figure.
- Adjust cavities, size and spacing, and check the 3D preview.
- Download the STL, print it in PETG and use the tray straight away, with no post-processing.
Sources and standards
The technical data in this guide relies on verifiable official sources:
