Storage & Containers

Canning Lids & Bands

Flat sealing lids and threaded bands that vacuum-seal mason jars for preserving.

Canning lids and bands are the two-part closures for mason jars: a flat metal lid with a sealing compound plus a screw band that holds it during processing. As the hot jar cools, the lid pulls down to form an airtight vacuum seal that preserves the contents. The flat lids are typically single-use while the bands can be reused.

Canning lids and bands are the two-piece metal closure that makes modern U.S. home canning possible. The flat disc (often called simply "the lid") is a tin-plated steel disc with a ring of food-grade plastisol—a soft sealing compound—molded around its underside. The threaded metal band screws over the disc and holds it down on the jar's rim during processing. When jars are heated in a water-bath or pressure canner, steam drives air out from under the lid, and as the contents cool, the contracting air pulls the lid into a slight concavity and forces the softened plastisol to mold itself to the glass rim, forming a vacuum seal.

The most important thing to know about this closure is that it is intentionally a one-way system. The plastisol ring is engineered to deform and flow into microscopic irregularities on the jar rim during heating, then harden in that shape as it cools. It will not reliably recover its original geometry, which is why flat lids are single-use. The screw band, by contrast, is just a piece of stamped steel that never touches the food directly and can be reused indefinitely as long as it is rust-free and undistorted.

Ball and Kerr are the dominant brands and their lids and bands are interchangeable across standard U.S. mason jars of the same size class. The two-piece Kerr design was patented in 1915 and replaced the earlier zinc-cap-and-rubber-ring closure. It is not used with European-style Weck jars (glass lids with separate rubber gaskets and wire clamps), nor with the bail-and-wire or zinc-cap closures found on vintage Lightning and Mason jars from the late 1800s and early 1900s.

Alternatives

Reusable Canning LidsClamp LidsWeck Glass Lids

Types & varieties

Regular mouth

~70 mm diameter; pairs with regular-mouth pints, quarts, and half-gallon jars; the workhorse size for most home canning

Wide mouth

~86 mm diameter; pairs with wide-mouth pints and quarts; the wider opening makes filling, de-bubbling, and cleaning jar rims easier, especially for chunky pickles, whole tomatoes, and halved fruit

Jelly jar size

Small diameter for 4 oz and some 8 oz jars; not interchangeable with regular mouth, so check the box carefully

Tattler reusable

Plastic disc with a separate white rubber gasket that can be reused for years; uses the same bands but a different sealing process—band is tightened fully, then backed off a quarter turn before processing, and retightened once jars are cool

Decorative printed lids

Same functional construction as standard lids with printed patterns on top; widely used for gifting dry mixes, cookies, and pantry storage

How the Vacuum Seal Forms

Understanding the physics of the seal helps prevent the most common canning mistakes. During processing, the air inside the headspace expands and pushes out around the lid, often bubbling through the contents. When heat is removed and the jars cool, the contents and the trapped air contract, creating negative pressure that pulls the lid downward and forces the still-warm plastisol to press tightly against the glass. As the plastisol cools, it solidifies in that compressed shape, locking the seal. Anything that traps air, prevents the lid from seating flush, or lets the plastisol cool in the wrong position can compromise the seal.

Wipe the jar rim clean before seating the lid—jelly, grease, or a stray seed breaks the seal.
Apply the band 'fingertip tight' so air can escape during processing; over-tightening can buckle the lid and cause siphoning (liquid loss).
After 12 to 24 hours of undisturbed cooling, the lid center should feel concave and not flex when pressed.
Remove bands for long-term storage; bands left on trap moisture, rust against the lid, and hide a failed seal.

Sizing and Brand Compatibility

The three diameter classes (regular, wide, and jelly) are not interchangeable. A regular-mouth band will not thread onto a wide-mouth jar, and a regular-mouth lid will overhang the rim of a jelly jar. Within a given size class, however, Ball, Kerr, and most generic store-brand lids and bands fit any standard U.S. mason jar of that class. Older jars with an unusual lip profile (some pre-1970s jars, and all European jars) will not seal reliably with current two-piece lids.

Common uses

Water-bath canning of high-acid foods such as jams, jellies, preserves, fruit, pickles, relishes, and salsas (when a tested recipe is followed)Pressure canning of low-acid foods such as vegetables, meats, soups, stocks, and beansAirtight dry storage of grains, beans, rice, dried pasta, spices, baking mixes, and other pantry staplesGifting homemade preserves, infused syrups, hot sauce, or layered dry baking mixesRefrigerated short-term storage of opened commercial goods, homemade condiments, and leftovers

Tips & pitfalls

Use each flat lid only once—the plastisol deforms during heat processing and will not reliably re-seal on a second run.
Wipe the jar rim with a clean, damp cloth before seating the lid; even a trace of jam, grease, or seed can prevent a vacuum seal.
Apply bands 'fingertip tight' only—over-tightening prevents air from escaping, can buckle the lid, and may cause siphoning of liquid during processing.
Remove the bands after 24 hours of cooling and before storing jars. Bands left on trap moisture, rust against the lid, and can mask a failed seal.
Confirm the seal by pressing the center of the cooled lid—it should feel concave and not pop back. A high-pitched 'ping' on cooling is a good sign.
Simmer lids (do not boil hard) for 10 minutes before placing them on hot jars, or follow the manufacturer's current directions—most brands now recommend a gentler warm-up.
Do not use lids with dents, deep scratches, dried-out or cracked gaskets, or any contamination. Discard any jar whose lid flexes, leaks, or whose contents smell off, look cloudy, or spurt on opening.
For Tattler reusable lids, tighten the band fully, back it off a quarter turn before loading the canner, and retighten once jars are cool—they seal differently than standard lids.
Keep bands matched to their jars (or mark them); a 70 mm band and an 86 mm band are not interchangeable, and mismatched pairs will not seat correctly.
Do not use mason jar lids in the oven, microwave, or with paraffin wax—they are designed for steam- or pressure-canning only.

Good to know

Components: Two-piece closure: flat sealing disc (lid) and threaded screw band (ring)
Material: Tin-plated steel lid with food-grade plastisol sealing compound; tin-plated or enameled steel band
Standard Sizes: Regular mouth (~70 mm), wide mouth (~86 mm), and small jelly jar (~58 mm)
Origin: Two-piece design patented by Alexander Kerr in 1915, replacing earlier zinc-cap and rubber-ring closures
Lid Lifespan: Single use only; the plastisol gasket deforms during heat processing and cannot reliably re-seal a second time
Band Lifespan: Reusable indefinitely if rust-free and undistorted
Storage: Cool, dry place in original packaging to keep the sealing compound clean and dry
Jar Compatibility: Interchangeable across Ball, Kerr, and other standard U.S. canning jars within the same size class