People search bath bomb mold sizes because a carton and a press do not match. This page is the spec door. It is not a second copy of bath bomb draft and release. RUUIPON pours the RTV halves in Bao'an, Shenzhen, since 2018. Production MOQ is 20 pieces per design after approval. A prototype is usually 3-7 business days after CAD lock.
Why we will not paste a universal size chart
Two shops can sell a "medium" bomb and pack different grams into the same outer diameter. Moisture, oil, and how hard you press change the fill. We will not invent a millimeter or ounce table and call it shop standard. If a project file later locks a size, we can add that row. Until then, you send the target.
We would not recommend copying an Amazon listing's inch number onto a custom tool if you have never weighed a packed bomb from that outline.
What to spec instead of a SKU number
If you send this, we can cut CAD:
- finished diameter you want on the shelf (mm preferred)
- packed grams from a test press, or a weight you must hit
- sphere, half-sphere, or a shaped outline
- whether a logo or stamp sits on the equator
- how many cavities you can handle in one press
- first mold quantity (MOQ 20 after approval)
Simple cavity CAD is about USD $50 when that scope applies. Photos plus a ruler beat a mood-board circle. After CAD lock: 3D-printed pattern, often a temporary silicone flip, resin production mother, then batch RTV. See services.
Two-piece sphere vs open dome
A full sphere is two halves and a registration story. An open dome is one peel. Size still comes first: a larger sphere that you cannot pack to the listed grams is a marketing size, not a tool size. Split and keys live on one-piece vs two-piece after the diameter is honest.
Worked example: same outline, two packed weights
Typical shop path, not a named customer. A brand sent one circle and two carton weights. The lighter mix filled the outline. The heavier mix mushroomed at the equator. We would not have cut one cavity and hoped both SKUs packed. We locked two cavity volumes, prototyped both in the 3-7 day window after CAD lock, and only then talked MOQ 20 per design.
FAQ
What size bath bomb mold should I order?
Send the finished diameter you want to sell and the packed grams you can hold in that outline. We will not publish a one-size chart that pretends every mix packs the same.
Do you have standard bath bomb mold sizes?
We make the cavity to your diameter and split. Catalog retail sizes exist in stores. If a store tray already matches the bomb, buy that. Custom is for your outline, stamp, or a split that a catalog half-sphere will not hold.
Is this the same as the bath bomb draft blog?
No. The blog covers draft, domes, and release. This URL is the size intake: diameter, packed weight, and whether the tool is two-part. Link that blog after the size is named.
What is MOQ?
Production MOQ is 20 pieces per design after sample approval. A prototype is usually 3-7 business days after CAD lock. Simple cavity CAD is about USD $50 when that scope applies.
Draft and sticky release: bath bomb mold blog. Other custom cavities: custom silicone molds. Send sizes on contact.