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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 
Temperature 15 - 25°C
Relative humidity 45 - 55%
Max lux 50
UV less than 30 µw/lumen
Display period 3 mths per 12 mths
Same Temp and RH
Eliminate light


Drawing – charcoal, crayon, gouache, ink  
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 
Temperature 15 - 25°C
Relative humidity 40 - 60%
Max lux 200
Max UV 75 µw/lumen
Display period 6 mths per 12 mths
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
Gesso Acid sensitive
Horn RH critical (45 – 55%)
Ivory RH critical (45 – 55%)
Leather - undyed, tawed Some sulphur sensitive, RH 45 – 65%
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 
Temperature 15 - 25°C        
Relative humidity 30 - 60%             
Max lux 300                           
Max UV 150 µw/lumen                      
Display period unrestricted         
Same Temp and RH        
Eliminate light           
Aluminium                    Acid and alkali sensitive 
Amber                         Solvent sensitive 
Ceramics, porcelain   40 – 60% RH
Copper, bronze, brass Less than 45% RH 
Enamel                         Temp sensitive
Glass                      40 – 60% RH
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 
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