Without adequate airflow, the humidity and concentration of other water soluble chemicals will rise therefore increasing the possibility of corrosion.  In ordinary circumstances this is not an issue, but where priceless artifacts are involved this becomes more pertinent.

Testing can be conducted on water based paints to determine whether they will tarnish precious decorative metals or not, such testing (known as the Oddy Test) is routinely used by many museums.

Oddy tests are used to determine whether paints can be used in storage and display situations in museums. In this test, a painted sample is enclosed with a portion of cleaned metal (normally lead, copper and silver) in an air tight container. Corrosion is accelerated by adding water to create high humidity and by elevating temperatures (60°C). After 28 days, the extent of corrosion on the metal section is used to evaluate the suitability of the material under test for use in the display or storage of artefacts containing that metal.

The Oddy test provides three recommendations from the results of the test:

• If there is no change compared with an untested metal the coating is considered safe to use.
• If any metal displays any sign of discolouration the coating is considered to be safe for temporary use within an enclosed environment.
• Obvious corrosion indicates the paint is unsuitable for use.

Dulux has tested and proven coating systems that meet the requirements for temporary and permanent storage of irreplaceable artifacts.  One such product that meets the requirements for permanent installations is Dulux Wash & Wear in all available sheen levels.