This decision is usually made on feel first and logistics second, and it should be the other way round as often as not. Both materials hold creams, balms, food and powders well. The differences show up in shipping, in how the product ages in the jar, and in how the customer handles it every day.
The short verdict
Choose glass when the product is premium, sensitive to air or moisture over a long shelf life, or filled hot, and when your shipping can protect it. Choose plastic when weight, breakage or price per unit drive the decision, or when the jar goes somewhere glass is unwelcome, such as a bathroom or a gym bag.
Three tradeoffs in favor of glass
| Factor | Glass jar | Plastic jar |
|---|---|---|
| Barrier | Non-porous and practically impermeable to oxygen and moisture, and unreactive with most contents | Varies by resin; some plastics let small amounts of gas through over time |
| Perceived quality | Weight, coolness and clarity read as premium | Clear PET can look glassy, but it feels lighter in the hand |
| Heat | Tolerates hot filling well, though sudden temperature changes can crack it | Standard PET softens with heat; PP handles heat better |
Three tradeoffs in favor of plastic
| Factor | Plastic jar | Glass jar |
|---|---|---|
| Weight | A fraction of the weight of glass, so freight costs less per unit | Heavy, which adds to every shipment |
| Breakage | Shatter resistant; dents or scuffs rather than breaking | Breaks if dropped, and needs inserts or dividers to ship safely |
| Material range | PET for clarity, HDPE for an opaque, chemically resistant jar, PP for heat | One material, varied by color, shape and thickness |
What the iBox product pages say
- Custom glass jars run from compact 10ml travel formats to 545ml pantry and salon sizes, with matching lids and roll-on applicator options, for skincare, cosmetic, food, essential oil and balm brands.
- Custom plastic jars come in PET, HDPE and PP, in capacities from a few ounces to large bulk formats, with closures for different applications.
- Custom PET jars are described as glossy and shatter resistant where glass would break.
- Custom HDPE jars are described as durable, chemically stable and moisture resistant, in milky translucent and opaque finishes.
Choosing for common products
- Premium face cream or balm: glass, unless the jar travels a lot with the customer.
- Body butter or hair product used in the shower: plastic, because wet hands and tiles are hard on glass.
- Supplement powder: HDPE, which is opaque and tough.
- Jam, honey or sauces filled hot: glass, or a plastic specified for hot fill.
- Samples and travel sizes: plastic for weight, or small glass if the brand is built on glass.
Do not forget the outer box
A glass jar that ships needs protection: a fitted insert, dividers or a sturdy mailer. A plastic jar can often travel in a simpler carton. iBox makes the printed boxes as well as the jars, so the jar and its box can be specified together, with free design support, free US shipping and a digital proof before printing. Box minimums start at 100 boxes per design.
Next step
Send the product, the fill volume, how it is filled, and whether it ships alone or in a box. Ask for a glass and a plastic option side by side on the quote form. For more on the plastics involved, see the custom plastic packaging page and what is mono material packaging.
