Arid

This climate is generally very dry, however, in arid areas, it is often very hot during the day and very cold at night. This wide fluctuation in temperature is matched by wide fluctuations in relative humidity, for example from 75%–20% in a day.

Leather which is exposed to these conditions is likely to become dry, hard and inflexible. Splitting and cracking are also likely. You can overcome these potential problems by adopting the following practices:

• store leather in cabinets, boxes and wrappers to buffer the objects against fluctuations in environmental conditions and to protect them from dust;

• make sure that any leather object is stored in the shape that the object is meant to have. If the object does then dry out and become inflexible at least the desired shape will be retained;

• ensure that any additional sources of heat are reduced. Exposure to daylight and ‘hot’ light sources, for example, should be avoided;

• leather objects should be stored and displayed away from external walls, fireplaces and similar sources of heat; and

• portable humidification units may be used during periods of prolonged low relative humidity.

Note: If your collections of leather objects have been stored in an arid environment for a considerable period and they are stable—do not try to alter the environment to meet the recommended ideal conditions. This could do more harm than good. The emphasis should be on long term stability.

Temperate

A temperate climate is considered a moderate climate, however, temperate climates tend to have a greater range of temperatures than tropical climates and may include extreme climatic variations.

Temperate climatic zones are considered to have moderate conditions. It should therefore be easier to maintain conditions reasonably close to those recommended for leather.

Care does have to be taken, however, to overcome the extreme climatic variations which still occur in these areas.

• storage and display in sealed cabinets will usually provide enough buffering capacity to overcome short term variations in relative humidity and temperature;

• wrappers, boxes and cupboards could all be used as layers of storage to provide buffering against changes in the external conditions; and

• regular inspections of the collections should be carried out.

Note: If your collections of leather objects have been stored in a temperate environment for a considerable period and they are stable—do not try to alter the environment to meet the recommended ideal conditions. This could do more harm than good. The emphasis should be on long term stability.

Tropical

These climates are characterised by heavy rainfall, high humidity and high temperatures.

In tropical zones high temperatures and relative humidities pose the greatest risk to leather objects. To minimise damage to leather objects in these areas the following strategies may be adopted:

• place sensitive leather objects in well-sealed cabinets and maintain the relative humidity below 65%.

• use cabinets, boxes and layers of non-buffered acid-free tissue to create buffer zones. This will reduce the impact of relative humidity and temperature fluctuations on leather. This is the “layers of storage” principle;

• portable dehumidification units may be used during periods of extremely high relative humidity;

• if RH control is not possible then ensure you have good air circulation to minimise the risk of mould growth; and
  inspect leather objects regularly and maintain high standards of cleanliness.

Note: If your collections of leather have been stored in a tropical environment for a considerable period and they are stable—do not try to alter the environment to meet the recommended ideal conditions. This could do more harm than good. The emphasis should be on long term stability.