Long-Term Storage Guide: Japanese Pottery, Lacquerware, Glass, and Cast Iron

Clean and dry each piece before putting it away, support it securely and choose wrapping that will not damage the surface. Then consider the storage place: iron needs protection from dampness, while lacquer also needs protection from excessive dryness and light.

This guide covers everyday cupboards, seasonal storage and keeping original boxes and records. Seek a conservator’s advice for fragile, repaired or valuable pieces whose condition is uncertain.

Keeping and using a paulownia box

A kiri-bako (桐箱) is a paulownia box. A tomobako (共箱) is an accompanying box with an inscription or attribution associated with the object, often through its maker. Keep such a box with the object’s records; handwriting alone does not establish authenticity.

A well-fitted box offers:

• Protection from knocks when the object is correctly supported.
• A place to preserve an original inscription and associated documentation.
• Lightweight, soft wood that can be shaped to support an object.
• Some buffering against environmental changes. The room still needs suitable conditions, and the box needs checks for moisture and pests.

When handling an original box:

• Keep its inscriptions and any accompanying records. Their value as evidence depends on how they relate to the piece.
• Photograph inscriptions on the lid and keep a separate digital record of the box and object together.
• Avoid heavy stacks or pressure on the lid. Even an empty box can be damaged; a loaded box also puts its contents at risk.

When there is no suitable fitted box, consider:

• Fitted cardboard box (acid-free).
• Unbleached cotton or linen wrap (loose, not tight).
• Acid-free tissue paper.
• A specialist can make a fitted paulownia box when that material is appropriate for the piece.

Choosing a storage place

Look for stable conditions, safe support and enough access to lift pieces out without knocking their neighbours.

Humidity: choose by material

Choose humidity conditions by material and condition. For context, CCI’s metal-storage guidance gives 35–55% relative humidity for stable metal objects in controlled mixed collections. Active corrosion needs specialist advice, and household cookware also needs its maker’s storage routine.

• Avoid places prone to dampness, heat or large temperature swings, such as basements, attics, garages and cupboards close to a stove.
• Choose a clean interior location away from direct heating or cooling airflow.
• A box or enclosure can moderate changes, but its performance depends on its materials, seal and monitoring.
• If you use a desiccant or humidity-control system, monitor it and maintain it as directed instead of replacing it by a guessed schedule.

Temperature: stable

Keep pieces away from direct heat, condensation and abrupt temperature changes.

Light: indirect or none

Keep lacquer, paper and light-sensitive painted decoration out of direct sunlight. Fired ceramic decoration and paint applied after firing can need different precautions.

Storage by material

Porcelain (Arita, Hasami, Kutani)

• Stack with unbleached paper or thin felt between pieces.
• Protect delicate or gold decoration from rubbing and pressure, using suitable soft separators.
• Open shelf storage is fine for everyday-use porcelain; closed cabinet for display pieces away from dust.
• See the Japanese porcelain care guide for washing and decoration care.

Cast iron (tetsubin, tetsu kyusu, furin)

• Dry iron according to its use and finish. An emptied tetsubin may dry with retained warmth and the heat off. Never heat an enamel-lined teapot or wind chime to dry it.
• Do not oil the inside of a tetsubin or enamel-lined teapot. Use exterior oils, waxes or other treatments only when the maker approves them for that finish.
• Support the object with suitable clean wrapping. Keep the original box as documentation; ask a conservator about an inert enclosure for valuable metal kept long term.
• Protect cast iron from dampness, which can cause rust even in an empty vessel.
• See the cast iron tetsubin care guide for drying.

Urushi lacquerware

• Use a dry fitted box and soft wrapping where suitable. Keep lacquerware away from direct sun, vents and extreme dampness or dryness.
• Wrap only when dry, using clean materials that will not catch on or react with the finish.
• Check occasionally for moisture, pests and changes in the finish.
• See the urushi lacquerware care guide.

Donabe (clay pot)

• Let the body and lid dry thoroughly. Moisture can remain in porous clay after the surface looks dry.
• Keep the lid off while drying and avoid trapping moisture when putting the pot away.
• A ventilated cabinet is useful for everyday storage; keep the pot protected from knocks.
• See the donabe care guide.

Edo Kiriko (cut glass)

• Wrap each piece individually in soft tissue paper or unbleached cotton.
• Avoid direct glass-on-glass contact and unsupported stacks.
• Use suitable individual wrapping and a fitted protective box. Old, decorated or unstable glass may need more specific conservation advice.
• See the Edo Kiriko care guide.

Kyusu (teapot)

• Dry with the lid off, checking that the interior and strainer are dry too.
• Store with lid placed askew on top of body, allowing air circulation inside.
• Avoid sealed plastic containers, especially for unglazed clay kyusu.
• See the kyusu care guide.

Matcha set components

• Dry the chasen in open air. A suitable shape holder can support the tines; never enclose it while damp.
• Store bowls individually where possible; use suitable soft separators if stacking them.
• Keep the chashaku clean and dry, protected from pressure in a suitable box or support.
• Clean and dry a natsume before storage, following its lacquer or other material instructions. Transfer matcha to a suitable airtight tea container for freshness.
• See the matcha set care guide.

Furin (wind chime)

• Take a chime down when the weather or season makes hanging unsuitable.
• For cast-iron furin, dry gently and follow the maker’s finish-care instructions. Do not apply oil automatically.
• Ceramic and glass furin: individual cotton or tissue wrap, no piece-on-piece contact.
• See the furin care guide.

Choosing wrapping materials

Use:

• Clean soft cotton or linen where it will not catch on fragile surfaces.
• Acid-free tissue paper — for fragile glass and ceramics; archival-quality.
• Conservation-quality paper appropriate to the surface. Check its specification; washi varies in composition and acidity.
• A fitted protective box suited to the object and its materials.

Avoid:

• Packaging that traps residual moisture. Stable plastics can be useful in conservation, but the material and enclosure must suit the object.
• Newspaper — acidic, transfers ink, breaks down into dust.
• Degraded cushioning or wrapping pressed against delicate surfaces.
• Unspecified acidic board or wood touching sensitive metal.
• Crumbling foam. Stable polyethylene foam can be suitable; deteriorating foam should be replaced.
• Tight wrapping or pressure on spouts, handles, raised decoration or thin rims.

Keeping pieces accessible and checking for changes

For pieces in regular use, leave enough space to retrieve them safely and keep soft separators between surfaces that rub.

Check pieces periodically during longer storage, more often if conditions fluctuate or the object is vulnerable. Look for:

• Condensation, damp wrapping or new surface haze.
• Rust on iron.
• New cracks, lifting or dulling in lacquer.
• Signs of insects or other pests.
• Cushioning or wrapping that has begun to break down.

Date your notes and photographs, and investigate new changes before repacking.

Storing older or valuable pieces

Keep a record of older or valuable pieces as well as protecting their surfaces.

Documentation

• Photograph the piece from multiple angles before storing. Include a scale reference.
• Photograph box inscriptions and any authentication documents separately.
• Store digital backups in cloud storage and on an offline drive.
• Maintain a written or spreadsheet log of each piece's storage date, condition, location, and any inspection notes.

Original packaging

• Preserve an original box as documentation even if it needs repair or a separate protective enclosure. Do not keep using a damaged box when it no longer supports the object safely.
• Keep certificates and purchase records associated with the piece in a suitable folder or enclosure.

Insurance and appraisal

• For valuable pieces, check the terms and limits of your own insurance policy and ask the insurer about any additional documentation required.
• Use a qualified appraiser when an up-to-date valuation is needed for insurance or another defined purpose.

Handling

• Use clean hands or suitable gloves according to the material and condition. Cotton gloves can reduce grip on smooth ceramics or glass; support the body with both hands and use a padded tray for fragile objects.
• Inspect over a clear, softly padded surface and avoid lifting by handles, spouts or rims.

FAQ

Can ceramics and lacquerware share a cabinet?

Yes, when the conditions suit both. Separate hard or rough surfaces from lacquer and delicate decoration, keep stacks light and allow enough space to lift each piece safely.

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Further reading: CCI on ceramics and glass and Yamada Heiando on lacquerware.