When it comes to materials you should use in your collection area, there are some you should avoid using if possible.
- Coloured tissues and fabrics as the colour may run if it gets wet.
- Newspapers and other types of acidic paper and tissue.
- Wool and rubber as they are sources of sulphur which causes metal corrosion. Wool is also very attractive to insects.
- Metal paper clips and staples that will eventually rust and cause staining.
- Blu-tack or adhesive tape that may come in contact with artefacts.
- PVC that is often found in cheap plastic storage enclosures. PVC also eventually becomes tacky and releases hydrochloric acid.
- Loose foam packing does not provide good protection for objects and makes them difficult to remove from boxes. Starch pellets can attract insects and disintegrate if they get wet.
- Polyurethane foams should definitely not be used with heritage materials as they become acidic and crumble over time.
Archival acid-free packing materials
Wherever possible, select archival and acid-free packing material from reputable conservation suppliers. Non-archival products may be high in acids and other harmful chemicals, which can damage collections over time. Products sold as archival or acid-free by non-conservation suppliers, such as art supply shops, may not be suitable for long-term collection use.
With that in mind, there are some materials that are great for object packing collection storage.
Acid-free blue grey board
Acid-free blue grey board can be used to make a whole range of boxes and supports for objects. It can also come in several pre-made box styles. Which are good for buffering humidity changes.
Pre-made conservation quality boxes
Some pre-made conservation quality boxes are made from polypropylene instead of acid-free board. This has the advantage of being relatively waterproof if you have a high risk of floods or water leaks. Ordinary polypropylene or polyethylene tubs from a hardware store can also be used to store collection items making them a cheap alternative.
If you cannot afford conservation quality boxes for your entire collection, you can upgrade ordinary boxes by lining them with acid-free tissue. This is essential for materials susceptible to acids such as textiles, metal, and paper but not materials such as ceramics and glass.
Acid-free tissue is good for general purpose wrapping of objects, and for padding out the folds of soft textiles. Using acid-free tissue helps to buffer humidity changes and prevent condensation. Remember there are two types of acid free tissue, buffered and unbuffered. Buffered tissue has faint stripes on it and feels slightly powdery. It is good for plant materials such as paper as it helps prevent acid migration. However, it is damaging for proteinaceous materials such as leather, silk, wool, ivory and bone and can also affect dyes and photographs. In these instances use unbuffered tissue. If you can only afford one kind of tissue, purchase the unbuffered.
Another really useful material is Tyvek is a kind of synthetic cloth. It is excellent for making cushions, storage supports, and covers for objects and shelves. It is also waterproof yet breathable, as long as it is used the right way round. The smoother side should face the object, while the fluffy side faces outwards. Tyvek can be joined with a sewing machine or heat sealer. As it is a non-woven material, it does not require hemming.
Washed white cotton, calico or japara can be used for covering objects.
Foams come in a variety of densities and thicknesses. The main types used in conservation are polyethylene foam and ethafoam. Polyethylene foam is quite soft with fine closed bubbles. It is generally fine to use against all but the most delicate surfaces. For very friable materials, polyester lining can be used to cover the foam by cutting a slot into it, and then tucking the fabric inside. Ethafoam is quicker and easier to cut into shape, but can be quite scratchy which is why we often cover it with a softer foam or fabric.
Cell-Aire polyethylene foam wrap can be used to line boxes or shelves, pad out folds in textiles and wrap objects for transportation.
Buble wrap with caution
Bubble wrap, on the other hand, is not archival and should not be used for long-term storage. The plastic bubbles can leave permanent impressions in many materials including paint and Perspex, and should never directly touch any objects. It is useful for wrapping objects that are being transported short distances but always wrap the object first in tissue or Tyvek with the bubbles on the outside.
Acid-free paper is useful for interleaving paper-based works and photographs. Paper materials can also be stored in acid-free paper envelopes, Mylar, ready-made archival storage albums, polyethylene or polypropylene sleeves.
Friable media such as charcoals and pastels should not be stored in plastic as there is a risk of damage from static electricity. Although it is less archival than other storage materials, Glassine paper is sometimes used to interleave materials in order to reduce physical damage.
Following these basic guidelines for storing the items in your collection, will really help you keep them in the condition they arrived in and will help your collection stand the test of time.
Thanks for listening.