Timber Characteristics 03

Harold Hall

Cabinet Making



"Quarter cut" boards, SK. 1a, will have a relatively straight grain with the growth rings in most cases not being over prominent. In some species it will produce what are called "medullary rays", short wavy lines of a lighter colour across the board. This is a very prized feature of oak and some other species, SK. 4. Many "through and through" boards will have a very pronounced pattern, SK. 4, the extent depending on the species in question and its position in the log when cut (those conforming to SK. 1c).


No enlarged copies of these pictures


Colour is another aspect to consider, not the differences between species, oak and mahogany typically, but differences within a particular timber type. There can be some difference in colour between one tree and another that  can be a problem if a largish quantity is required.

Of greater significance, even when only a board or two is required, is that there is a difference in colour between the heartwood and the outer sapwood. Because of this sufficient excess wood must be purchased to give some scope for colour matching. Defects in the timber supplied, knots, splits, etc. also dictate a need for some excess wood.


Surprisingly, the colour difference between heartwood and outer sapwood is not a gradual condition but changes almost entirely over a few growth ring.


Photo 2 shows two boards jointed with that on the left showing a marked difference between the heartwood and its outer sapwood appearing to make only a small portion usable, that in the top middle. However, Photo 3 shows the other side and providing it can be given a position where the first side is hidden it can be used in full. In this case it was a low level shelf in the cabinet seen on the final page of this item.  Otherwise only the top centre of the left board would be usable so as to eliminate the lighter wood.