Classic Mason Jars

The mason jar takes its name from John Landis Mason, who patented a threaded glass jar with a reusable screw closure in 1858. A molded thread on the glass let households seal preserves again and again without wax or wired-on lids, and the later two-piece lid — a flat disc that seals on the rim and a band that holds it in place — kept the name.

Today ‘mason jar’ describes a finish standard as much as a shape: a bead and continuous thread sized for 70 mm or 86 mm lids, which is why lids interchange across the category. We supply the classic straight-sided body in both mouth sizes, from small preserve jars to one-liter storage jars.

Small-batch and craft food brands use mason jars for fruit preserves, raw and creamed honey, fermented vegetables, chutneys, infused oils, dry mixes and overnight oats. The wide mouth suits chunky or set products that are spooned out; the regular mouth suits pourable sauces and is cheaper to cap.

The jar also has a long second life as a drinking glass, storage jar or gift container — cafés serve cold drinks in it, and gift brands fill it with granola or bath salts. That reuse value is part of its retail appeal, so it pays to design the label and lid with it in mind.

Mason jars run heavy on purpose. A thick base and rounded heel help the jar cope with hot filling and line handling, and the broad sealing bead gives a plastisol-lined disc a wide, forgiving surface to seal against. Regular-mouth jars use a 70 mm finish; wide-mouth jars use an 86 mm finish that opens the shoulder almost to the full body diameter.

Measurement marks, fruit motifs or a recessed label panel can be cut into the mold. Deep body embossing reduces label contact area, so we check your artwork against the embossing layout before tooling.

For shelf-stable preserves, mason jars are usually hot-filled or water-bath processed. Leave a consistent headspace so the lid can pull down and form a vacuum, and don’t over-tighten bands before processing — air needs to vent. Once the jar has cooled, the center of a disc lid should be concave and firm.

Soda-lime glass handles hot filling but not sudden thermal shock, so avoid filling boiling product into a jar straight from cold storage. Disc lids are single-use for sealing because the compound sets on first closure. Tell us your process and we’ll match the lid and liner to it.

Mason jars are formed on the press-and-blow process: a plunger presses the glass gob into a parison, which is then blown to its final shape. This gives the even, relatively heavy wall the format needs. The jars are then annealed to relieve internal stress and coated at the hot and cold ends to protect the surface and help them run smoothly on filling lines.

We can supply flint or colored glass, embossed logos and measurement scales, printed or frosted decoration, and complete lid sets in gold, silver, black or custom print. Stock sizes are available as samples for fit and filling trials.