Readability, Reversibility, Stability are the three essential rules introduced by Paul Philippot*. These are based on principals established by Césare Brandi**.

 

1. Conservation treatments must be perceptible during a close examination but be embedded into the overall work discretely.

2. Products and materials used can be removed without affecting the object.

3. The ageing of the products must not damage the object, but ensure its long-term stability. This notion goes with the respect of the compatibility of chosen materials with original materials. So it is not weakened or altered.

 

Preventive Conservation and minimal intervention

The rather late origin of these two principals appeared in the 1980’s.

The first one refers to any direct or indirect actions, which aim to slow down ongoing damage. Stabilised, its longevity is ensured. Different preventive measures may be taken if objects are stored in a museum, a religious building or a private housing; such as:

- A regular dusting

- A control of temperature (between 18° and 22°) and hygrometry in every room (better to keep it below 60% to prevent the development of microorganism.

- Avoid direct exposure to sunlight and heat (candle, radiators, fire place).

 

One of the primary objectives is to preserve the original materials to the maximum, which defines minimal intervention. This is why it is intrinsically linked to preventive conservation.