Storage and display

An object on display is being watched. An object in a store is not, and that is where it spends the overwhelming majority of its existence. Storage is therefore where preventive conservation has the most leverage per pound spent, and it is consistently the least glamorous line in any budget.

Enclosures do four jobs

A box, folder or wrapping is not just a container. Done properly it buffers humidity, excludes light entirely, forms a barrier to insects and dust, and provides physical support so the object is not handled directly. Done badly it becomes a source of acid, a moisture trap or a hiding place.

The specification that matters is chemical and physical, not the adjective on the catalogue page. For paper-based enclosures you want to know the pH, whether it is lignin-free, and whether it carries an alkaline reserve. For plastics you want to know the polymer: polyester, polyethylene and polypropylene are the standard safe choices, while PVC is not, because it plasticises and off-gasses. For photographic material there is a specific test, the Photographic Activity Test, and enclosures intended for photographs should state that they pass it. Acid-free boxes and tissue covers the detail, including where buffering is wrong.

Shelving and racking

The failure modes here are mundane and expensive: overloading, sharp edges, unstable stacking, and materials that off-gas.

Powder-coated steel is the default for good reasons, being strong, inert once cured and easy to clean. Wooden shelving in an enclosed store is the standard mistake, for the reasons set out in air quality: it emits organic acids for years. Where wood is already installed and cannot be replaced, sealing it and boxing the objects reduces the exposure considerably.

Beyond material, the questions are practical. Can a shelf be reached without a stool? Is there space to put an object down before turning round? Is anything stored above head height that a person will have to lift down at arm’s length? Most handling damage happens in the two seconds around a bad reach. Shelving and racking covers layout as well as specification.

Display cases

A case is simultaneously a security enclosure, a dust barrier, a humidity buffer and, if built from the wrong material, a pollutant chamber. The four requirements pull against each other, and the main variable that decides how it behaves is the air exchange rate.

A leaky case is a dust barrier and nothing more. A well-sealed case can hold a humidity band for months with a modest quantity of conditioned silica gel, but the same seal that makes that possible also concentrates any pollutant emitted inside it. This is why case material testing is not optional for sealed cases and why the Oddy test exists. Display cases covers construction, glazing and the trade-off between sealing and ventilation.

Handling and movement

Physical force is the agent of deterioration that produces the most immediate, obvious and avoidable losses, and almost all of it happens during handling.

The rules are simple and get broken under time pressure: plan where the object is going before lifting it, carry one object at a time, support the whole object rather than a projecting part, use a tray or a board rather than fingers, and never carry an object through a door you have not already opened. Handling and gloves covers the glove question, which is less settled than it used to be.

For anything leaving the building, the packing case does the work. Shock, vibration and rapid climate change are all worse in transit than anywhere else, and a case that buffers all three is a specialist item rather than a strong box. Transport and crates covers what to specify and what to log during a journey.