Andrew F in Australia
>Hi Bill, Richard and Wiley,

Following on from Richard's comments, it also could be postulated that the timber is dried to a level where it will remain stable in the workshop - at 70-75% humidity and comfortable temperatures, timber contains approximately 13.5% moisture. It has to be stable in here to allow the thing to be made accurately. We just design to have it move as it gets drier (eg: airconditioned environment at 40% RH.)

US Forest Products laboratory - data source

Just another possible data point.

Cheers,

Andrew

Working in about 80-90% humidity outside at the moment and losing the fat from the christmas pudding quickly (he says with hope.)