Caring for modern materials

The term modern materials typically refers to items in museum collections created after the 1800s, through the rise of industrialisation, mass production of substitute luxury goods, and artistic experimentation. These materials are engineered and man-made, and can include plastics, pigments, binders, coatings, fabrics, and electronic and time-based media.

Conservation approaches for modern synthetics are still developing and are not as well understood as those for materials with years of ageing data behind them, such as stone or metal. Plastic-based materials and objects are complex in their manufacture, and their specific requirements for longevity are still being understood. Identifying what you have and documenting it for other users is central to preserving modern materials.

Modern materials are diverse and complex. They can be any scale, from a faux ivory hatpin to large sculptures and artworks, and can form part of other items, such as buttons on costume. They pose unique preservation issues and are not always identifiable as a modern material until they begin to show signs of deterioration.

This decay can be unpredictable. It can make items unstable and occur at a higher rate than with other collection materials, depending on what they are made of and how they have been used, stored, or treated in the past. Modern materials can be acutely affected by the environment. They can also affect other collections nearby, through reactions to past cleaning methods or airborne pollutants, especially in enclosed spaces with limited airflow.

The main threats to modern materials are:

Pests and micro-organisms

Modern materials are not as susceptible to common museum pests as organic material. However, they may carry organic material such as sweat deposits or oils, or excrete substances that then attract dust, mould, mildew, or pests. Insects or rodents can chew them or use them as nesting material.

Chemical degradation

The formulations used in manufacture, and the long-term instability of some plastics and synthetics, mean that temperature, relative humidity, ultraviolet, and visible light can all make polymer degradation worse. This results in warping, loss of strength, flexibility, or colour, weeping of plasticisers, and ultimate loss of the material.

Off-gassing and cross-contamination

Modern materials can threaten other collections, especially in a confined space or in direct contact with another item, if they emit volatile organic compounds or acidic gases.

Past treatments

How an item has been cleaned, stored, displayed, and conserved in the past all affects its preservation. It is not always clear whether undocumented or experimental repair methods, pollutant-emitting cleaning agents, or storage materials have contributed to changes in a modern material’s integrity, stability, or longevity. The negative effects of these treatments may only now be becoming visible as more of the synthetic material ages.

Technical obsolescence

Loss can come from more than the deterioration of the physical material. It can also come from the format and medium required for the material to be heard, read, displayed, used, or interpreted. Your collections may no longer be accessible because of the types of technology, electronics, kinetic art, or media used.

Components that have been replaced, lost, or have failed, or motors that have worn out, cannot be repaired if there are no trades or skilled makers to supply replacement parts. You may not be able to read items such as hard drives if you no longer have the supporting technology. For technology that will become obsolete, migrating data or documenting content into a usable, accessible format preserves information before it is lost to researchers or the public. Review your collection to make sure you prioritise these modern materials.

Modern materials, like other museum collections, can pose chemical, physical, and biological threats to you, your visitors, and your collections. Understand the method of manufacture of each item and any possible threat. Seemingly stable items can be dangerous. Early twentieth-century televisions, for example, contain cathode-ray tubes that were used to create the screen image and can implode, contain heavy metals, cause electrical shock, or emit radiation.

Review any suspect material, record it, and put appropriate measures in place. If the item is significant or a priority, such as a loan, list possible hazards for emergency response and add any safe handling measures to your emergency plan. The MGS guide to hazards in collections covers these risks in detail.

Identifying what your modern material is made of is not a one-size-fits-all process. Its exact molecular makeup can vary considerably, and it can be difficult to know exactly what was used. A mixture of unknown engineered compositions, experimental recipes, multiple materials, or varying, non-standard methods of manufacture, with few items carrying makers’ marks, makes identification complicated and sometimes daunting.

Narrowing down the characteristics of your item against known materials gives you a better understanding of what you are dealing with. Non-invasive methods and analytical techniques are preferred over taking samples or using methods that can cause damage, loss of original material, or leave holes in the item.

Ways to help you identify a material:

• Visual: look at and compare colour, grain, imperfections, surface crazing, signs of seams or manufacture, and transparency. Magnification aids inspection.
• Touch: feel whether it is warm (plastics warm quickly to the touch) or cool (like real ivory). Does it feel sticky? Modern materials in active decay may feel sticky or look like they are weeping.
• Smell: does it emit a smell? Use caution. Rubber can smell sulphurous, PVC or vinyl can smell fishy or like chlorine, and cellulose nitrate can smell like vinegar.
• Sound: how does it sound if lightly tapped? Does it sound hollow (some plastics), ring (like brass or silver), or thud (like wood)?
• Spectroscopy: techniques such as Fourier-transform infrared spectroscopy (FTIR) or Raman spectroscopy measure how molecular bonds interact with light, creating a unique molecular fingerprint to identify the exact polymer and any additive.
• X-ray fluorescence (XRF): identifies the elemental composition of items. As each element produces a unique energy signature, this helps determine whether traditional or modern synthetic elements have been used in the object, paint, or medium.

Contact an object or modern materials conservator or curator if in any doubt. The Modern Materials Group can help with resources and contacts

Knowing the condition of your modern materials, as well as their composition, helps you allocate resources for their care. Use robust protocols when documenting information. Record material history in your database and note hazards, attaching hazard signage to suspect items so you and others stay aware of any changes and can respond more quickly or reduce risk. The MGS guide to condition checking explains how to record condition consistently.

Take care to understand what material you are marking when applying unique accession numbers. Solvents can cause some modern material surfaces to melt, become tacky, or lose colour, and numbers can be indented into surfaces if you use too much pressure.

When displaying modern materials, consider both the continued preservation of these collections on display and any other collections or supporting objects that could be affected. This is particularly important in showcases, where you may need to reduce off-gassing, condition the environment, or provide bespoke mounts and lighting, as well as address safety considerations for the item or the public on open display.

Modern collections may carry the additional aspirations of the maker or artist, who may have stipulated how an object should be displayed to preserve the integrity of the art. This creates challenges in maintaining gallery light levels, or in bringing materials into gallery spaces that could promote pest activity or need additional resources.

Some modern material, because of its known hazards, may have to be contained or removed from the object to allow public access and protection, such as radioactive gauges or dials in cars or planes.

Modern materials, like other museum collections, are best preserved in clean, pest-free, environmentally monitored and controlled stores. Some need specific conditions to delay deterioration or prevent them becoming hazardous, such as cold storage for cellulose nitrate film.

As plastic and synthetic materials break down, they emit acids that damage other collections. Organise stores to allow for division that reduces exposure from contact or off-gassing.

Not all plastics were designed to last long term, so specific conditions, such as oxygen-free environments, may prolong lifespan. For rubbers and polyurethanes, which are highly susceptible to oxidation, oxygen-free storage prevents cracking and crumbling.

Think carefully about the storage materials and systems you use, to make sure your storage is not promoting decay. Modern artworks may need strict climate control, as modern paints and synthetic media are especially sensitive to fluctuating temperatures and high relative humidity. If you cannot control the whole storage area, create micro-climate areas or rooms within a room to buffer collections within your store. This can save energy by focusing resources.

Routine housekeeping

Visually inspect modern collection items for any areas of damage or deterioration that may alert you to risks your treatment could pose. Where possible, identify the material before you surface clean it, even before dusting.

Modern materials can be easily scratched by abrasive dust particles. Cleaners containing solvents can discolour surfaces or cause them to chemically alter or break down

When handling and moving modern collections, be aware of any potential damage to the item or yourself. Make sure you and your teams or volunteers understand what the item is made of and how it might react to lifting, vibration, or a change in environment before any move.

Some modern materials were used to repair or replicate another material, such as epoxies and polymers, or metallic powders and hardeners in plaster of Paris for stone or metal items. Be aware that some of the substrate may be weaker than it appears.

Consider your approach to handling. Use nitrile gloves to prevent transfer of oils from skin and to protect handlers, add physical support, or isolate the material from more sensitive collections. If hazardous elements are present, secure, remove, or isolate them. Enlist specialist movers or conservators if the item needs dismantling or a controlled environment.

Check the environmental conditions in the area the item is in and where it is going, in case a change instigates a chemical reaction or thermal shock, or causes irreversible damage such as sunlight causing photodegradation in plastics.

Different modern materials react to fire and water in different ways, and some are hazardous, which can make an emergency harder to deal with. A clear, active emergency plan is essential. It should identify these hazards and set out how to reduce the risk and how to respond if an incident happens. List where any significant or unstable modern materials are kept, such as cellulose nitrate, along with their hazards, so your team and emergency responders can act safely and quickly.

The Scottish Council on Archives has produced emergency planning guidance for collections with practical advice on preparing for incidents.

Scotland has dedicated networks for specialist help during emergencies. Find contact details on the Scottish Council on Archives page listing emergency response networks across Scotland.

For more collections care guidance, find our other advice guides on collections.

The Plastics Historical Society offers resources on the history and identification of plastics through its Plastiquarian website.

Museum Textiles has produced a guide to modern materials in textile and costume collections.

The Canadian Conservation Institute has produced guidance on the care of objects made from rubber and plastic.

The Science Museum Group has published information on caring for its collection.