Glass jars and bottles do more than just hold your product. They protect what's inside, help your brand stand out, and make it easier for people to use. Whether you're bottling cold brew, jarring chutney, or launching a new skincare product, picking the right glass container is about more than looks. It's about getting the function right too.

Let's run through what to look at when choosing glass packaging

 that is right both for your product and your consumers.

Start with the Product Itself

Your product will typically decide your glass and closure type. If you're dealing with acidic foods or essential oils, the glass won't react—but possibly the lid. Some products will eat through certain cap liners, so oily or acidic formulas must be paired with phenolic caps and liners like PTFE or pulp and foil. For plastisol-lined hot-filled jam or chutneys, use twist-off caps.

If your product is heat-treated, like hot-fill, pasteurisation, or retort, your jars need to resist sudden changes in temperature. That goes for closures too—they must be able to seal and stay sealed while the glass is warming and cooling.

And if your product is light-sensitive—such as vitamins, essential oils, or anything with natural colour—use amber glass wherever possible. Green glass or UV-block coatings will also be beneficial, but amber is the best bet for protection from light.

Get the Size and Headspace Right

Start by thinking about how much your customer will eat in one sitting. For jams, sauces, and spreads, standard sizes are 200 ml to 350 ml. For drinks, individual servings will be 250 ml to 355 ml, and shared bottles 500 ml to 750 ml.

Leave a little room at the top. Hot-fill and you'll require headspace for expansion. It's foamy or aerated and you'll need room for the bubbles. Too large and you're shipping empty air and wasting extra postage. Too small and customers are going to be upset.

Match the Neck Finish with the Proper Closure

The neck finish of the bottle or jar dictates what cap will fit. Get this wrong and nothing will close.

Threaded (CT) finishes are the standard default for sauces, creams, supplements, and the like. They're everywhere in a range of diameters like 38-400.

Lug or twist-off finishes are for pickles and preserves and are particularly well-suited to plastisol linings for hot-filled foods.

ROPP (roll-on pilfer-proof) finishes are used on spirits and high-end drinks and are capped with aluminium caps.

Crown finishes are used on carbonated drinks like beer or soda and need to be crimped.

If you're packaging skin care, serums, or essential oils, chances are you'll include pumps, droppers, or spray tops. Make sure they are suitable for your product's thickness and won't clog or over-dispense. You may also need tamper-evident bands or child-resistant closures, based on the product and regulation.

Consider Shape and Functionality

The design of the jar or bottle affects how people utilize it, how it's stored, and how well it pours.

Hexagonal packaging is attractive, but flat sides are difficult to label and reduce the way you can stack them on pallets.

The shape also affects grip and pouring or handling ease. Narrow waists, wide shoulders, or rounded sides can all add to comfort use. Wide mouths accommodate chunky contents or anything to be scooped out. Thin necks reduce spills and facilitate pouring.

For liquids like oils and syrups, you might have to add an orifice reducer to regulate flow and avoid huge spills.

Think about where the product will be placed too. Is it into a kitchen cabinet, restaurant backroom, or bathroom shelf? Each of these has different space, handling, and breakage risks.

Inspect Label Area and Decoration Options

You'll need a flat area where labels can stick without wrinkling or peeling off. Tapered or curved bottles look nice, but they make it harder to label them so that labels are more challenging to straighten out—and restrict how much information you can show.

Decide at the outset whether you are using self-stick labels, which are quick and flexible, or spending money on screen printing or ceramic ink, which give a higher-end finish and better durability. If you want something special, embossed glass can build your branding into the mould, but that is costly and time-consuming.

Make Sure It Complies with Safety Standards

For food products, it's not just the glass that matters—it's the whole system. Caps and liners must be food-safe and compliant with regulations in your region. If you're selling in the UK or EU, or exporting, check for food-contact approval, recycling codes, and any specific rules around alcohol, supplements, or child safety closures.

Lot tracking is also important—especially for recalls—so make sure your cap and jar suppliers offer that.

Keep an Eye on Lead Times and Supply

Those cute designs are great, provided that you can have them when you require them. Always inquire with your supplier about:

  • Minimum order quantities (MOQs)
  • Lead times for jars and lids
  • Pallet sizes (so that you can stock them and ship them)
  • Packaging strength—especially for shipping. Ask for drop-tested shipper boxes or actual dividers
  • Long-term supply. Can they promise the same shape and mould next year? Even a small variation can mess up your labels

Be Honest About Sustainability

Glass is recyclable, but it's heavy—and that contributes to your transport impact. There are a few ways to reduce your environmental impact without greenwashing:

Use lighter-weight jars where possible. Search for "eco" or "NNL" versions that cut weight without compromising strength.

Try refill or return programs for local shoppers.

Place explicit recycling information on your labels, and avoid convoluted packaging like foil wraps or multi-component closures that cannot be easily recycled. 

Always Test Before You Commit

Before you purchase in quantity, test your entire packaging system:

  • Make sure the torque levels so the caps seal tightly but do not become stuck.
  • Do leak tests, like turning bottles on their heads and leaving them for a day.
  • Do thermal shock tests, especially if you're hot-filling or cold-storing quickly.
  • Do a short shelf-life test to spot colour changes, flavour drift, or carbonation loss.

Write it all down—it'll help your quality control team and it will give you confidence that the product will last in the real world.

Good packaging is not just about aesthetics—it's about how your product, process, and customer experience come together in harmony. When you get the formula right, the jar or bottle is nearly invisible. It simply works.

Select packaging appropriate to your formula, your brand, and your supply chain. Pilot on small scale before production runs. And remember: the right glass container will protect your product and make the user's life easier—whether to pour, scoop, or spread.

If you'd like it to be for a product brochure, technical manual, or B2B landing page, I can alter the tone and structure accordingly. All you have to do is let me know what it is for, and I'll shape it to meet your needs.