Containers

Clear, and what it costs

On this page10

The archetype's position What clear gives you That second one is underrated What opaque gives you So the answer splits by use And a label solves most of it The 35 are a real set Amber is a middle position Decide per jar, not per collection References

The gap is real. Here is what is on each side of it.

The archetype's position

"Displayed as much as stored. Clarity matters more than anything else." That is a fair description of how collectors treat a cabinet, and it describes a quarter of this shelf.

What clear gives you

Identification without opening, which for a sealed jar is the whole point: every opening replaces the dry atmosphere with the room. It also lets a humidity indicator card be read through the wall.

That second one is underrated

A sealed jar with an indicator you can read without breaking the seal is a self-reporting system. In an opaque jar the indicator is only useful at the moment you open it, which is the moment it stops being accurate.

What opaque gives you

Light exclusion. Some metal surfaces change under light and many inks fade, and a black or amber container removes that variable entirely for material that is being stored rather than shown.

So the answer splits by use

Display or active working material goes in clear. Long-term storage of anything light-sensitive goes in opaque, with the identification on the label rather than through the wall.

And a label solves most of it

A good label on an opaque jar does everything a clear wall does except show the indicator. Writing what is inside, when it was sealed and when the desiccant was changed is better practice than looking anyway.

The 35 are a real set

Mostly PET single wall jars across the size range. If clear is the requirement, that is the list, and it is deep enough to build a consistent system from.

Amber is a middle position

15 containers. It blocks the short wavelengths that do most of the photochemical work while still letting you see that something is in there, which for a working collection is often the right compromise.

Decide per jar, not per collection

There is no reason a collection has to be in one kind of container. The pieces you look at monthly and the pieces you have not opened since 2019 want different things.

References

The Davis Pack Supply catalog, measured 18 October 2026. The numismatic and philatelic shelf is 391 rows: 146 containers and 245 closures. 81 PET, 64 PP and 1 glass, from 6 to 250 mL with a median of 118. Zero PVC. By colour 39 white, 35 clear, 23 black, 15 amber, 15 natural and 8 blue. Necks 70-400 at 113, 89-400 at 93 and 58-400 at 66.

National Park Service, Conserve O Gram, on the storage of metal objects: metals corrode in the presence of moisture and pollutants and should be housed below 35 percent relative humidity, stabilised in a dry microclimate using a desiccant such as silica gel. Deteriorating plastics emit acidic vapours that corrode metal, which is why a metal coupon is used to detect an off-gassing plastic. nps.gov

Written from Library of Congress and NARA preservation guidance and from National Park Service Conserve O Gram material, and from the catalog as it stood on 18 October 2026. Conservation advice for a specific object is a job for a conservator; nothing here is a substitute for one, and a valuable or unusual item deserves that conversation rather than a jar.