Table of Contents
Client: FH Packaging (fhpkg.com) Main keyword: double wall plastic jars Suggested meta title: Single Wall vs Double Wall Plastic Jars: Complete Buyer’s Guide Suggested meta description: Compare single wall and double wall plastic jars on cost, capacity, shelf appeal, weight and recyclability, plus how to choose the right one. Links placed: 2
- double wall plastic jars → https://fhpkg.com/collections/double-wall-plastic-jars
- single wall plastic jars → https://fhpkg.com/collections/single-wall-plastic-jars
Two jars sit side by side. They are the same height and the same width. One holds twice as much product as the other.
That is the single wall versus double wall question in one sentence, and it catches out a lot of new brands. They order what looks like a generous jar, then find out it holds far less than the size suggested.
Here is how the two constructions actually differ, and how to pick the right one.
What the two constructions are
Single wall jars are made from one layer of plastic. What you see from the outside is the inside. Simple, light and efficient.
Double wall jars are two containers in one. An inner cup holds the product, and an outer shell surrounds it with an air gap between them. From the outside it looks like one thick, solid jar.
Both are usually made from PP (polypropylene) or PET, and both use standard continuous thread neck finishes such as 58-400, 70-400 and 89-400.
The capacity trap
This is the most important thing to understand before you order.
With a double wall jar, the air gap sits between the inner and outer walls. That space holds nothing. So a double wall jar with the external size of a 4 oz jar might only hold 2 oz of product.
Suppliers list double wall jars by their fill capacity, not their external dimensions. A “2 oz double wall jar” holds 2 oz but occupies noticeably more shelf and shipping space than a 2 oz single wall jar.
Practical consequences:
- Fewer units fit per carton, so freight cost per unit goes up
- The jar takes more shelf space in a retail display
- Ecommerce shipping boxes need to be larger
- Customers may perceive the product as generous, or as under-filled, depending on how you present it
Neither outcome is automatic. It depends entirely on your market and your price point.
Why brands choose double wall anyway
Given the extra material and shipping cost, why is double wall plastic jars construction so common in skincare?
It signals value. A thick-walled jar with visible depth in the base feels substantial in the hand. For a 30 ml eye cream selling at a premium price, a tiny single wall jar can make the product feel underwhelming even when the formula is excellent. The double wall gives physical presence that matches the price.
It hides the fill line. As a customer uses the product, a clear single wall jar shows the level dropping. The opaque outer shell of a double wall jar hides that entirely.
It allows two finishes. The inner cup and outer shell can be different colours or materials. A white inner with a frosted or metallised outer is a common premium look that is difficult to achieve on a single wall jar.
It offers modest insulation. The air gap provides a small buffer against temperature swings. This is a minor benefit and should not be the main reason you choose it, but it exists.
Why single wall is often the better choice
Lower cost per ounce of product held. Per unit, prices vary by material and size. Per ounce of actual fill, single wall is almost always cheaper because you are not paying for a second shell.
Better shipping economics. Lighter and smaller for the same capacity means lower freight, which compounds across large orders.
Simpler recycling. A single wall plastic jar made from one material can go into a single recycling stream. Double wall jars are more complicated, especially where the inner and outer parts are bonded or made from different plastics. If sustainability claims are part of your brand, this is a genuine consideration.
Full transparency where you want it. If your product looks good, a clear single wall jar sells it. Colourful scrubs, layered balms and textured products all benefit from being visible.
Larger sizes are practical. At 8 oz and above, double wall construction becomes bulky and expensive. Single wall is the standard choice for bigger formats.
Side by side
| Single wall | Double wall | |
| Cost per ounce held | Lower | Higher |
| External size for same fill | Smaller | Larger |
| Weight | Lighter | Heavier |
| Perceived value | Standard | Premium |
| Shows product level | Yes, if clear | No |
| Recycling | Simpler | More complex |
| Best size range | 1 oz to 16 oz and up | 0.5 oz to 4 oz |
| Two-tone finishes | Limited | Easy |
Which products suit each
Single wall works well for:
- Body butters, scrubs and larger format products
- Hair masks and treatments
- Bath salts
- Value and mid-market skincare
- Any product where you want customers to see the contents
- Brands with a stated sustainability position
Double wall works well for:
- Eye creams and night creams
- Serums in jar format
- Small-volume, high-value formulas
- Luxury and prestige skincare
- Products sold at a premium where shelf presence matters
- Lines that need a specific colour or finish combination
Material matters as much as construction
Do not decide construction without also deciding material.
PP (polypropylene) is opaque or translucent, has good chemical resistance, tolerates heat well, and is the usual choice for double wall jars. It handles a wide range of cosmetic formulas.
PET is clear, glossy and has good barrier properties for many products. It is common in single wall straight sided jars and shows contents well.
PETG and acrylic appear in premium jars where a glass-like appearance is wanted without the weight or breakage risk of glass.
Always run a compatibility test with your actual formula. Essential oils, high alcohol content and certain actives can interact with plastics and liners over time. A jar that looks fine on day one can distort, cloud or leach after three months.
Do not forget the closure and liner
The jar is only half the package.
- Match the neck finish. A 70-400 lid fits any 70-400 jar. Order by finish, not by jar size.
- Choose the right liner. Pressure sensitive liners work for many dry and semi-solid products. Heat induction seal liners give tamper evidence and a better barrier, but need sealing equipment. Foam and polyethylene liners suit simpler applications.
- Consider a shive or disc if your product is soft and you want a clean surface presentation.
- Check headspace. Fill volume and brim capacity are different numbers. Ask your supplier for both.
Quick decision guide
Ask yourself these in order:
- What is my retail price? Above a certain point, presentation starts to justify double wall cost.
- How much product am I filling? Above 4 oz, single wall is usually the practical answer.
- Do I want the product visible? If yes, single wall in a clear material.
- Is recyclability part of my brand promise? If yes, lean single wall and mono-material.
- What are my freight costs? High shipping volumes make the size difference add up quickly.
Common questions
Is double wall stronger? Not meaningfully. Both constructions are durable. The extra shell adds bulk and appearance, not structural strength you would notice in normal use.
Can I get double wall in clear? Yes, though it is less common. The effect is different from a clear single wall jar and worth seeing as a sample before committing.
Do they use the same lids? Yes, if the neck finish matches.
Which is better for the environment? Single wall uses less material and is easier to recycle. If sustainability is a priority, that is the clearer option.
How do I know the real capacity? Ask for both fill capacity and brim capacity, and confirm external dimensions separately. Never assume from the product name.
Final thoughts
Double wall jars are a presentation choice. They cost more per ounce, ship less efficiently and complicate recycling, and for the right product they are absolutely worth it.
Single wall jars are the practical default. They are cheaper, lighter, simpler to recycle and better suited to larger sizes.
Work out your price point and your fill volume first. Those two numbers will usually answer the question before you have looked at a single sample.