Closures and liners
Updated
On this page8
What is here
235 closures against these necks: 210 continuous thread, 21 dome lids, 2 specialty, 1 lug and twist and 1 sealing disc. By liner, 64 HIS, 42 F217, 31 pressure-sensitive, 26 none, 21 standard plastisol, 19 PE foam and 15 foam.
Gasket or membrane, again
Foam, F217 and plastisol compress against the land and seal while the cap is on. An induction liner bonds to the land and stays sealed with the cap off. For a moisture barrier held over seasons that difference is the whole thing.
Which is why the HIS set matters here
Sixty-four closures carry it. It is the only liner shape on this shelf pointing toward a package that could be argued to maintain viability for twenty-four months, and it needs an induction sealer in your process.
Dome lids are for display, not storage
Twenty-one of them. They suit a jar meant to be looked at and opened often, and they are the wrong choice for anything held against a two-year window. Knowing which job the jar has settles it quickly.
No liner is sometimes deliberate
Twenty-six closures carry none, which suits a container where something else seals or where a liner material would be unsuitable. It is a choice rather than an omission, and for seed storage it is the wrong choice.
Desiccant is a component too
With a capacity, a shelf life once opened, and a size that has to suit the headspace. It is cheap and it is routinely the part nobody specifies, which is how a sealed jar ends up with a saturated sachet in it.
Standardize, then prove it with retained samples
One neck, one closure, one liner, one induction setting across the range. Then keep sealed samples from each run and germinate one later, because that is the only measurement of your package rather than of your seed.