In order to transport water over vast lengths while fighting gravity forces, the cell structure of the wooden vessels in the trunk has to be very strong.
This explains why the core of a tree is considered more durable than the outer part. The bark transports the sugars from the leaves back to the roots. This high sugar content can cause mould in a moist environment. This is why outer sapwood (bark) should not be used in furniture.
A-Grade Teak is the premium centre cut of the teak timber and makes up about 30-40% of the timber. It is cut from mature teak trees, and unlike lesser quality teak wood Grade A teak offers a consistent look without knots, discolourations, or other unwanted variations.