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.

When caring for textiles in arid areas it its important to note that:

• insects can still survive;

• in very dry conditions, textiles will give out the moisture they contain and will tend to become more brittle; and

• non-fabric components of the textiles may be adversely affected by very dry conditions and consideration should be given to this, even if the textiles themselves are stable.

Remember that even arid areas have periods of higher relative humidity, even though the periods may only be very short.

The system of layers of storage—acid-free material sandwiching the textiles, boxes and rollers in cupboards—is particularly suited to arid areas because of the tendency to get quite marked fluctuations in temperature and relative humidity. Many arid areas are also very dusty and so the layers of storage protect the textiles from dust and grit.

Because of the large temperature fluctuations in arid areas, there is a risk that condensation could form inside frames. It is important to have a spacer in your frames to keep framed textiles out of direct contact with the glazing material, otherwise mould could grow inside the frame.

Note: If your textiles collections 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.

It is probably easier to achieve the recommended ideal conditions for the storage of textiles in a temperate climate, however, it is unlikely that you will be able to maintain an even environment without the help of sophisticated air conditioning equipment.

The system of layers of storage—acid-free material sandwiching the textiles, boxes, boxes and rollers within cupboards—will be very useful in helping to buffer against the extreme conditions that can occur in a temperate environment.

As for all climatic areas, regular inspections of storage and display areas are important so that developing problems do not go unnoticed.

Note: If your textiles collections 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.

When caring for textiles in high humidity conditions it is important to note that:

• insects and moulds thrive and reproduce readily;

• the rate of deterioration due to light and UV radiation increases;

• different components of single objects will take up moisture at different rates and swell by different amounts. For example, a cotton core in a metallic thread will expand and contract in response to fluctuations in relative humidity, but the metal does not change as readily. This causes abrasion to the cotton core thread; and

• gelatine sequins on19th century costume can swell and become sticky in high relative humidity conditions, and can stick to the underlying fabric.

Remember that in tropical areas, air flow is important and this should be taken into account when designing storage and display systems.

Note: If your textiles collections 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.