Closures and liners
On this page11
What is here
245 closures: 201 continuous thread, 22 dome lids, 9 liners and sealing discs, 6 round tub lids and 3 specialty.
By liner
63 carry an induction-seal liner, 42 F217, 31 PS, 19 PE foam, and 27 carry none. That distribution is the real content of this page.
Induction seal is the strongest option
A foil liner bonded to the rim gives a genuine barrier. It needs sealing equipment, which puts it out of reach for a collector sealing one jar and within reach for anybody doing it at any scale.
F217 is the practical one
A foam liner that compresses against the rim. No equipment, reusable across openings, and a good seal if the closure is tightened properly and the rim is clean.
No liner means no seal
27 of the closures here carry none. For a dust cover that is fine, and for a microclimate it is not, and the difference is invisible until a desiccant exhausts early.
The liner is in the sealed space
Whatever it is made of is in a closed atmosphere with the collection for years. That is an argument for specifying it rather than accepting whatever comes on the cap.
Necks worth standardising on
70-400 at 113 and 89-400 at 93 carry most of this shelf, then 58-400 at 66 and 53-400 at 33. Staying on one of the first two keeps both the closure and the liner choice wide.
Test a sealed jar before trusting a collection to it
Seal one with an indicator card and nothing else, leave it in the storage location for a month, and read it. That is the whole validation and it costs one jar.
Dome lids are a display choice
22 of them. They look considered and they are not a sealing closure, so they belong on a cabinet rather than on anything being stored for decades.
Match the closure to how often it opens
An induction seal is for something closed once. A compression liner is for something opened annually. Choosing the stronger seal for a jar you open monthly produces a broken seal rather than a better one.