and

  Vellum

   Recommended:

• Total darkness whenever possible;   Protection from strong light (natural or artificial) and UV light for material in use

  Recommended:

• 18C - 20C or cooler  

  Recommended:

• between 50% and 55% RH

  Acceptable:

• shortest duration and least intensity of exposure possible

  Acceptable:

• As close as possible to recommended range;   minimal and gradual seasonal fluctuations  

  Acceptable:

• 40%  to 45%

  Not acceptable:

• High light levels; direct sunlight; fluorescent lights without UV shields.

  Not acceptable:

• above 25C; large daily temperature swings

  Not acceptable:

• Over 55% RH; under 40% RH; Any fluctuations beyond the 5% range which an archives has established as its norm for storage

• Total darkness whenever possible; protection from strong light (natural or artificial) and UV light for material in use

Recommended:

• 18C - 20C or cooler

Recommended:

• 40% and 45% RH

Acceptable:

• shortest duration and least intensity of exposure possible

Acceptable:

• As close as possible to recommended range; minimal and gradual seasonal fluctuations

Acceptable:

• 35%  to 55%

Not acceptable:

• High light levels; direct sunlight; fluorescent lights without UV shields.

Not acceptable:

• above 25C; large daily temperature swings

Not acceptable:

• Over 55% RH or below 35% RH; daily fluctuations in excess of 3% to 5% RH