Sometimes temperature change may alter the shape of the bamboo or wooden frame underneath the lacquer and produce a hairline crack in the surface. Good quality preparation in the workshop will minimize, but not eliminate the chance of these cracks that appear within a few weeks of exposure to cold winter air. Exposure to direct sunlight can also produce the same effect. The best way to minimize tarnish is to keep silver away from freely circulating polluted air by putting silver wares in an enclosed case and silver jewelry in a jewelry box or even a sealed plastic bag. After sitting for a minute, the foam and tarnish are easily removed under the faucet.
Polishes improve the appearance of the finish and also help to preserve the wood.
The frequency will depend on the character and density of the wood. Teak will benefit from a polish every 4-6 months while ebony wood may only need it once a year. An old toothbrush can be a useful tool for getting polish into finely carved folds and furrows. When tropical woods are brought to a temperate climate, the woods contract as they dry out. The contraction creates stress that increases in relation to the diameter of the wood.