At the same fill volume a glass lip balm jar lands at a higher cost than a plastic tube, and no amount of negotiation closes that gap. Glass earns its place when the product is finger-applied (lip masks, tinted balms, solid perfume), when the formula is rich in oils and butters that attack plastic, or when weight and recyclability are part of the brand story. Many brands that run both put the hero SKU in glass and extend the line in plastic. If glass is the choice, the decisions that follow are jar profile, closure and liner, and how the jar behaves on a hot-pour line.
When glass is worth the extra cost over a tube
Glass suits lip care brands positioned above the plastic-tube tier, formulators of solid perfume and balm-to-oil products, and private-label programs that sell on heft and recyclability. The technical argument is inertness: essential oils and butters can plasticize some plastics or strip flavor into them, while glass does not react with the formula.
The environmental argument is less clear-cut. Glass is heavier to ship but infinitely recyclable, so a "clean beauty" claim should rest on both recyclability documentation and shipping-weight data rather than on the material alone. If the goal is the lightest possible pack, plastic wins. For stick formats and other alternatives, the cosmetic glass category shows what else is available.
Jar pricing is quoted per project. The drivers are jar weight, cap material, decoration, packing, quantity and freight terms, and because small glass jars are dense, freight weighs more heavily than buyers used to plastic expect.
Wide-mouth or straight-sided
Profile decides how product goes in and how the customer gets it out.
Wide-mouth, low-profile jars (38–43mm opening on a 15–30ml jar) are the finger-application format for lip masks, overnight treatments and tinted balms. A fingertip needs a clear bore of 18mm+ as a practical minimum, and 25mm+ is comfortable. These jars fill quickly on piston depositors because the nozzle has room, at the price of more glass per ml.
Straight-sided jars (taller than wide, 22–33mm opening) suit concentrated products such as solid lip serums, cuticle balms and solid perfume. They take less carton space per unit and read as apothecary on shelf, but the taller wall slows cooling of hot-pour wax: plan on 10–20% more cooling tunnel time. Neighboring shapes are in the small glass jars with lids range.
Whichever profile you pick, avoid any shoulder or neck restriction. Lip formulas pour at 65–85°C and set fast, and a restriction traps air at the shoulder line, leaving a visible void in the finished product. In the 5–15ml range, ask for truly straight walls or an internal base radius of 10mm+. Every jar in the table below meets that rule.
Sizes, finishes and container loads
| Model | Capacity | Profile | Finish | Jar weight | Pieces per 40HQ | Cap options |
|---|---|---|---|---|---|---|
| LB-3 micro | 3ml | Straight, mini | 28-400 | ~16g | ~600,000 | PP screw, aluminum |
| LB-5 straight | 5ml | Straight-sided, low | 33-400 | ~22g | ~420,000 | Aluminum, PP screw |
| LB-7 wide | 7ml | Wide-mouth | 38-400 | ~28g | ~350,000 | Aluminum, bamboo |
| LB-10 straight | 10ml | Straight-sided | 38-400 | ~34g | ~300,000 | Aluminum, PP, bamboo |
| LB-15 wide | 15ml | Wide-mouth, low-profile | 43-400 | ~46g | ~230,000 | Aluminum, bamboo |
| LB-15 tall | 15ml | Straight-sided, tall | 38-400 | ~42g | ~250,000 | Aluminum, PP screw |
| LB-20 wide | 20ml | Wide-mouth | 48-400 | ~58g | ~190,000 | Aluminum, bamboo |
| LB-30 low | 30ml | Wide-mouth, low-profile | 53-400 | ~72g | ~150,000 | Aluminum, bamboo |
The container figures assume bulk-packed jars with caps in separate cartons. The 15ml wide-mouth sells in the largest volume because it takes a standard 0.5oz lip mask fill and still leaves proper headspace. Larger and deeper formats are listed with the cosmetic jars sold in bulk.
Custom capacities and the weight floor
An unusual capacity, such as a 12ml jar nobody else stocks, or a signature base profile makes sense when the shape itself identifies the brand or when annual volume is high enough to carry the tooling. Small molds are the least costly in glass because the blanks and mold blocks are small, and sampler jars down to 2ml have been tooled. The limit is wall thickness: press-and-blow needs about ~1.6mm at this scale, so a 5ml jar cannot drop much below 16–18g however it is drawn. We handle this through custom cosmetic jar projects.
Caps and liners that hold up against wax, butter and flavor oil
Waxes, butters and flavor oils migrate into liners and can stress-crack some plastics, so the cap is chosen with the formula in hand.
- Liner. For balms, specify a food-grade PE liner. Plastisol can absorb flavor oils over 6+ months and pass odor back to the product. Standard foam liners break down under high-butter formulas and shed particles during shelf life, so those formulas need an oil-resistant liner specification.
- Aluminum. Aluminum caps dent in transit if the cartons are weak. We specify 350gsm+ dividers for shipments with aluminum caps.
- Bamboo. The bamboo is a shell over a threaded PP or aluminum core; bamboo should never be threaded directly or touch the product. It also needs a moisture-content spec of 8–12% so it does not crack in dry retail air. Details are on the page for glass jars with bamboo lids.
Small finishes of 33–43mm are capped at 6–10 in-lbs. Overtightened aluminum caps are the leading cause of chipped threads on small jars, so the fix is calibrating the capping heads. The same torque window, together with a PE-foam liner specified for 25%+ compression set resistance, is what stops caps backing off in transit and leaking at retail.
Running small jars on a hot-pour line
A 15ml jar on a rotary piston line runs at 40–80 units per minute, but cooling is normally the bottleneck. A 75°C wax pour needs 90–150 seconds in the tunnel before capping; cap sooner and the lid traps a surface skin and the product sinks.
Thermal shock is the second concern. Pouring 75°C formula into a 20°C jar creates a 55°C differential. The annealing spec we set (polariscope grade ≤3) covers differentials of 42°C+, which is enough for standard pour temperatures into room-temperature jars. If you pour above 90°C or fill in an unheated building in winter, pre-warm the jars to 35–40°C on the conveyor.
Base flatness matters at speed. Jars that are out of flat tip on accumulation tables and jam labelers. The spec we work to is ±0.3mm, and if your line exceeds 60 units per minute it is worth asking for base-flatness data with the samples.
Inspection and compatibility checks
Three defects account for most trouble with jars this small:
- Chipped finishes. Checked by finish-gauge inspection at AQL 2.5 and torque sampling on each lot, with a reject threshold of 0.4% critical defects.
- Thermal shock at filling. Controlled by the annealing grade above and, where needed, jar pre-warming.
- Oil bleed through the cap liner. Verified by accelerated aging at 40°C/75%RH for 4 weeks against your formula or a reference balm. Sending 500ml of bulk formula with the order lets the test run on the real product.
Each lot ships with an FDA food-contact compliance statement, and buyers in the EU receive EU 10/2011 migration documentation.
Packing and shipping weight
Jars travel in divider cartons of 25–100 pieces depending on size, with caps nested separately, on ISPM-15 plywood pallets that avoid fumigation holds. Under standard export packing, breakage runs 0.3–1%, which makes small jars among the most transport-tolerant glass formats.
Weight is the thing to plan for. A 40HQ of 15ml jars holds ~230,000 pieces and 10+ tonnes of glass, so confirm container and road weight limits on your route; some US door-delivery lanes force dense small-glass loads into 20GP splits. Below ~25,000 units LCL works well, because divider cartons cope better than bulk pallets with the 3–5 handling events an LCL shipment goes through. The document set is the invoice, packing list, certificate of origin, FDA food-contact statement and migration data.
What to send for a quotation
- Capacity and profile: wide-mouth or straight-sided and the fill volume, or a drawing or sample to match.
- Formula: pour temperature and oil or butter load, which set the liner spec and the thermal advice.
- Closure: aluminum and its color, PP or bamboo, plus a liner preference if you have one.
- Quantity per SKU and destination, so freight can be worked into the landed figure.
- Decoration: plain, label panel dimensions, or screen-print artwork with its color count.
FAQ
Can an order be split across several cap colors?
Jars and caps are quoted separately, so a split is possible. Stock aluminum colors (silver, gold, black) divide more easily than custom cap colors or bamboo, which depends on wood-batch economics. Quantities are settled per project.
How do I test my formula in the jar before committing?
Sample, inspection and claims terms are agreed for each project before an order is placed. The liner aging test described above is the usual compatibility step.
Can you match a jar my contract filler already runs, or one I want to dual-source?
Yes. Send the physical jar or the filler's spec sheet. We match finish, height and label panel so chucks, torque settings and labelers carry over without re-tooling. Base diameter is the dimension to verify against the conveyor guides, since a 2mm difference can mean guide adjustments, and we flag it in the match report before changeover.