Buying cosmetic jars wholesale from China turns on two numbers most buyers never ask for: the brimful capacity and the packing density. A jar labelled 50g rarely holds exactly 50g of your cream, and jars ship badly — freight can take a larger share of landed cost than the jars themselves.
Jars look simpler than bottles. No pump, no dip tube, a wide opening. That simplicity hides a different set of problems: capacity mismatch, lid sealing, and the double-wall decision that quietly doubles your freight bill.
This guide covers jar construction types, how capacity is actually measured, sealing, wholesale price structure, and why shipping cost deserves a line in your comparison sheet.
Single-wall or double-wall?
This is the first decision and it affects cost, weight, freight and recyclability all at once.
| Type | Construction | Why buyers choose it | Trade-off |
|---|---|---|---|
| Single-wall | One moulded body | Lighter, cheaper, packs tighter, easier to recycle | Looks less premium on shelf |
| Double-wall | Outer shell plus an inner cup, air gap between | Thick-walled premium look, hides the product level | Heavier, bulkier, harder to recycle, roughly double the material |
| Acrylic outer, PP inner | Clear acrylic shell over a PP cup | Glass-like clarity without the weight of glass | Acrylic cracks on impact; never let it touch the formula |
| Glass | Single-wall glass with a plastic or metal lid | Genuinely premium, chemically inert | Heavy, breaks in transit, highest freight cost per unit |
The double-wall trap is worth stating plainly. A double-wall jar makes a 30g product look like a 50g product, which is why it sells. But you pay for the extra material, you pay for the extra volume in the container, and the air gap traps moisture during shipping in humid conditions.
There is also a direction-of-travel issue. Mono-material packs — one resin, no glued or press-fitted second layer — are easier to recycle, and brands making sustainability claims are moving away from double-wall for exactly this reason.
If the premium look matters, a heavier single-wall jar with a thick base gives much of the same effect at lower freight cost. Ask your supplier for a section drawing showing base thickness.
Why does a 50g jar not hold 50g?
Because jars are moulded to a volume in millilitres, while creams are sold by weight in grams. The two only match when the product density is exactly 1.0, and most cosmetic formulas are not.
Three capacity figures matter, and suppliers do not always say which one they are quoting:
| Term | What it means | Why it matters |
|---|---|---|
| Brimful capacity | Volume when filled level to the very top rim | The number moulds are designed to; always larger than usable capacity |
| Working capacity | Volume with normal headspace left below the rim | What your filling line will actually deliver |
| Labelled weight | Grams of product declared on the pack | Depends on your formula density, not on the jar |
Two things to do before ordering:
- Ask for brimful capacity in millilitres, in writing. Not “50g jar” — that is a marketing name, not a specification.
- Fill a sample with your actual formula and weigh it. Fill to the level you intend to ship at, then weigh. That number is your real fill weight.
Headspace matters more than buyers expect. Too little and product squeezes out when the lid is closed, leaving residue on the thread. Too much and the jar looks under-filled, which generates complaints. Aim for a headspace you can hold consistently on your filling line, then check that it looks right with the lid off.
How do cosmetic jars seal?
The lid alone rarely seals a jar. There is almost always a second component, and choosing the wrong one is the most common cause of leakage in transit.
| Sealing method | How it works | Best for |
|---|---|---|
| PE foam liner in the lid | Compressible disc that presses against the rim | Thick creams and balms, most common option |
| Inner lid or disc | Separate disc sitting on the product surface | Reduces air contact, adds a premium feel |
| Induction seal | Foil sealed to the rim by heat | Tamper evidence and best protection, needs a sealing machine |
| Gasket in the lid | Moulded silicone or rubber ring | Thinner products, reusable jars |
| Shrink band over the lid | Tamper evidence only, no sealing function | Retail requirement, never a substitute for a liner |
The last row is a common misunderstanding. A shrink band proves the jar has not been opened. It does nothing to stop leakage. If your only sealing measure is a shrink band, expect product on the outside of jars after a long shipment.
Practical test before mass production: fill sample jars, seal them exactly as you plan to in production, invert them, and leave for 48 hours at room temperature and again at elevated temperature. Then check the thread area for residue.
Product-specific format guidance for creams and balms is covered in our Vietnamese article on jars for moisturisers and creams.
Which defects are specific to jars?
Bottles crack at the shoulder. Jars fail differently.
- Lid too tight or too loose. The jar and lid are often moulded on different tools. Thread fit must be checked on parts from the same production run, not on early samples.
- Rim not flat. A warped rim means the liner cannot seal all the way round, and the jar leaks on one side only.
- Sink marks on a thick base. Thick sections cool unevenly and dimple. Very visible on clear jars.
- Inner cup loose in a double-wall jar. The cup rattles or lifts out when the lid is unscrewed.
- Haze or crazing in acrylic. Fine cracks from stress or from contact with actives. Acrylic must never touch the formula.
- Colour mismatch between jar and lid. Two components, two mould runs, sometimes two plants. Always approve them together.
- Stacking deformation. Wide, thin-walled jars deform under the weight of cartons stacked above them.
Defect one and defect six share a root cause: jars are two-part products. Approve the jar and the lid as an assembled set, from the same production batch, and keep one assembled set as the sealed reference sample.
How does wholesale pricing actually work?
Jar pricing has more moving parts than a single unit price suggests.
| Cost element | Behaviour | What to ask |
|---|---|---|
| Unit price of the jar body | Falls in steps at quantity breaks, not smoothly | Ask for the full price break table, not one quantity |
| Lid and liner | Often quoted separately | Confirm whether the quoted price is the complete assembled jar |
| Colour | Stock colours cheapest; custom colour has a batch minimum | Ask for the stock colour card before requesting a custom match |
| Decoration | One-off setup plus a per-unit rate | Separate the setup fee from the running rate |
| Carton and packing | Usually included but confirm it | Ask units per carton and carton dimensions |
| Freight | Driven by volume, not weight, for plastic jars | Ask for total cubic metres for your quantity |
The second row catches people out repeatedly. A quote of a few cents per piece may be for the jar body alone. Once the lid, the liner and the inner disc are added, the complete assembled jar can cost substantially more. Always ask: is this price for the complete jar as I will receive it?
Ordering several sizes at once usually improves your position, because the factory runs them in one production block. Ask whether quantities across sizes can be combined to reach the next price break — often they can, and buyers rarely ask.
Minimum order quantities by level of customisation are set out in our Vietnamese guide on minimum order quantities for cosmetic packaging.
Why freight matters more for jars
This is the part missing from most jar comparisons, and for large orders it can change which supplier is actually cheapest.
Jars are wide and short. They pack badly. A carton of jars is mostly air compared with a carton of tubes or flat bottles. Sea freight is charged on volume for light cargo, so you pay for that air.
| Factor | Effect on freight | What you can do |
|---|---|---|
| Double-wall construction | Roughly doubles the volume per unit of product held | Compare landed cost, not unit price, against a single-wall option |
| Lids packed separately | Can improve packing density significantly | Ask whether lids ship unassembled and who assembles them |
| Nested or stacked design | Some jar shapes nest; most do not | Ask for units per carton and carton dimensions before choosing the shape |
| Glass jars | Heavy enough that weight, not volume, sets the rate | Budget freight separately; do not assume plastic rates |
Practical method: ask every supplier for units per carton and carton outer dimensions. From those two figures you can calculate cubic metres for your order quantity and compare landed cost properly. Two quotes with the same unit price can differ meaningfully once freight is included.
The second row is a genuine lever. Shipping lids separately and assembling locally can raise the number of jars per container, though it adds a labour step at your end. Worth calculating for large orders.
Stock jars or custom moulds?
For jars, stock moulds cover more ground than they do for bottles. The shape range is narrower and the standard sizes are well established, so a stock jar rarely looks like a compromise.
| Route | When it fits | Note |
|---|---|---|
| Stock jar, stock colour | First run, market testing | Fastest and cheapest path to a finished product |
| Stock jar, custom decoration | Most brands, most of the time | Frosted finish, custom lid colour and good printing carry the identity |
| Stock jar, custom lid | Budget allows one distinctive element | The lid is what the customer sees first — best value differentiator |
| Fully custom mould | Proven volume, shape is a real differentiator | Tooling cost, longer lead time, mould ownership must be agreed in writing |
Row three deserves attention. With jars, the lid dominates the visual impression because it faces upward on a shelf. Investing in a distinctive lid — a wood-effect cap, a metallised ring, a soft-touch finish — usually gives more visible differentiation per unit of cost than reshaping the jar body.
Browse available jar moulds in our catalogue, including PETG jars in 50g, 80g and 100g, acrylic jars in 15g, 30g and 50g and round PP jars in 200g. The wider range is in our cosmetic packaging catalogue.
Checklist before your first jar order
- Is brimful capacity stated in millilitres, in writing?
- Has a sample been filled with your actual formula and weighed?
- Is the quoted price for the complete assembled jar including lid, liner and any inner disc?
- Have jar and lid been approved together, from the same production batch?
- Is the sealing method decided, and is it something other than a shrink band?
- Has a leak test been run at room and elevated temperature after 48 hours inverted?
- If acrylic is used, is the product-contact layer PP or PETG rather than acrylic?
- Do you have units per carton and carton outer dimensions from every supplier quoted?
- Has landed cost been compared, not just unit price?
- Is there a sealed reference sample of the assembled jar held by both sides?
Items eight and nine are the ones that change decisions on large orders. Everything else protects quality; these two protect the budget.
The bottle equivalent of this checklist, covering resin choice and neck finishes, is in our guide on cosmetic bottle manufacturing in China. The overall sourcing process — factory versus trading company, samples, inspection — is covered in our guide on cosmetic packaging manufacturing in China.
About VEENI
VEENI — SẢN XUẤT GIA CÔNG CHAI LỌ MỸ PHẨM TẠI TRUNG QUỐC
Cosmetic packaging manufacturing and sourcing in China.
What we do: design consulting, supplier sourcing, sample development, production management at the factory, and import handling. Our import experience is primarily into Vietnam — if you need delivery to another market, tell us the destination and we will confirm what we can arrange before you commit to anything.
- Hotline: 0933 439 668
- Email: Veenivietnam@gmail.com
- Address: LK 15-VT29, Khu nhà ở Xa La, P. Phúc La, Q. Hà Đông, Hà Nội, Vietnam
Frequently asked questions
Why does a 50g cosmetic jar not hold exactly 50g of cream?
Because jars are moulded to a volume in millilitres while creams are sold by weight in grams, and the two only match when product density is exactly 1.0. Ask for brimful capacity in millilitres in writing, then fill a sample with your actual formula and weigh it to get your real fill weight.
Should I choose single-wall or double-wall jars?
Double-wall gives a thicker premium look and hides the product level, but uses roughly double the material, takes up far more container space and is harder to recycle. A heavier single-wall jar with a thick base gives much of the same visual effect at lower freight cost.
Is a shrink band enough to stop jars leaking?
No. A shrink band is tamper evidence only and has no sealing function. Jars need a PE foam liner in the lid, an inner disc, an induction seal or a moulded gasket. If the only measure is a shrink band, expect product on the outside of jars after a long shipment.
Can acrylic jars hold cosmetic formulas directly?
No. Acrylic is an outer shell material — it gives glass-like clarity but cracks under impact and can craze on contact with actives. The product-contact layer should be a PP or PETG inner cup. Always approve the assembled jar, not just the outer shell.
Why is freight so important when buying jars wholesale?
Jars are wide and short, so they pack badly and a carton is mostly air. Sea freight is charged on volume for light cargo, meaning you pay for that space. Ask every supplier for units per carton and carton outer dimensions, then compare landed cost rather than unit price.
Related articles
- Cosmetic bottle manufacturer in China: resin, neck finish and wall thickness
- Cosmetic packaging manufacturer in China: factory direct sourcing guide
- Jars for moisturisers and creams (Vietnamese)
- Minimum order quantities for cosmetic packaging (Vietnamese)
- Sourcing cosmetic packaging from China (Vietnamese)
