generate questions: In heartwood it occurs only in the first and last forms. Wood that is thoroughly air-dried retains 8–16% of the water in the cell walls, and none, or practically none, in the other forms. Even oven-dried wood retains a small percentage of moisture, but for all except chemical purposes, may be considered absolutely dry.
What does wood retain in its cell walls despite being air-dried? {sep_token} Air-dried wood keeps up to what percentage of the water in its cell walls? {sep_token} What kind of dried wood retains a small quantity of water but is considered absolutely dry?