Appendix 2: Environmental Criteria for Materials
The information in this appendix was compiled from ‘Museum Methods: Practical Manual for Managing Small Museums’, Section 3 Preventive Conservation (Museums Australia Inc. NSW 1994) and adapted to accommodate recent changes in environmental guidelines for particular material types.
Minimal relative humidity (RH) fluctuations are essential to prevent damage to susceptible materials. Well sealed display cases give additional buffering to environmental changes and pollution ingress. Very sensitive and sensitive materials should be rotated on and off display as indicated.
| Environment | Materials | Special conditions |
|---|---|---|
| Very Sensitive Materials | ||
| Display: Temperature 15 - 25°C Relative humidity 45 - 55% Max lux 50 UV less than 30 µw/lumen Display period 3 mths per 12 mths Storage: Same Temp and RH Eliminate light |
Baleen |
|
| Cardboard | ||
| Drawing – charcoal, crayon, gouache, ink | ||
| Feathers | ||
| Fur, hair | ||
| Lacquer (oriental) | RH critical | |
| Leather dyed | ||
| Nylon | RH 60 % preferred | |
| Paper, works on paper | RH critical | |
| Parchment | RH ~ 55% preferred and Temp sensitive | |
| Pastel | Fragile surface | |
| Photographs | 16 - 20 °C, RH 30 – 40% | |
| Plant material, seaweed | ||
| Tapa | RH critical | |
| Textiles, including hemp | Dust free | |
| Water colours | ||
| Sensitive Materials | ||
| Display: Temperature 15 - 25°C Relative humidity 40 - 60% Max lux 200 Max UV 75 µw/lumen Display period 6 mths per 12 mths Storage: Same Temp and RH Eliminate light |
Bakelite, casein | Casein – RH 60 % preferred |
| Bitumen | Dust free | |
| Bone | RH critical (45 – 55%) | |
| Canvas | Dust free | |
| Composite frame mouldings | ||
| Coral | Acid sensitive | |
| Cork | ||
| Fibreglass | ||
| Gesso | Acid sensitive | |
| Horn | RH critical (45 – 55%) | |
| Ivory | RH critical (45 – 55%) | |
| Leather - undyed, tawed | Some sulphur sensitive, RH 45 – 65% | |
| Linoleum | ||
| Paint, protective coating | ||
| Paintings, oil, tempera, acrylic | RH critical (45 – 55%) | |
| Shell, mother-of-pearl, pearl | Acid sensitive | |
| Shellac | Temp. sensitive | |
| Tortoiseshell | RH critical (45 – 55%) | |
| Wax | Temp & solvent sensitive, dust free | |
| Wood, bamboo, cane, straw, wicker | RH critical | |
| Non-sensitive Materials | ||
| Display: Temperature 15 - 25°C Relative humidity 30 - 60% Max lux 300 Max UV 150 µw/lumen Display period unrestricted Storage: Same Temp and RH Eliminate light |
Aluminium | Acid and alkali sensitive |
| Amber | Solvent sensitive | |
| Brick | ||
| Ceramics, porcelain | 40 – 60% RH | |
| Copper, bronze, brass | Less than 45% RH | |
| Enamel | Temp sensitive | |
| Glass | 40 – 60% RH | |
| Gold | ||
| Iron, iron alloys | Less than 35%RH | |
| Lead | Less than 45%RH, organic acid and formaldehyde sensitive | |
| Marble, some sandstone | Acid sensitive | |
| Plaster | Acid sensitive | |
| Silver | Less than 45%RH, sulphur sensitive | |
| Stone | Less than 20 °C, RH 45 – 55 % | |
| Tin/tin plate | Less than 45%RH | |
| Plastics | ||
| Display: Temperature as low as practical Relative humidity less than 50% Max lux 50 Max UV 30 µw/lumen Display period 3 mths per 12 mths Storage for most plastics: Temperature 2 - 5°C Relative humidity less than 50% Eliminate light Reduced oxygen environment |
Acrylic plastics e.g. perspex | Solvent sensitive, display period 9 mths per 12 mths |
| Magnetic tape (audio/video) | Use copy, cool store original | |
| Micro forms (fiche/films) | Use copy, cool store original | |
| Plastics | Cool, oxygen free best, off gas pollutants | |
| Rubber | Cool, oxygen free best, off gas pollutants | |