Roasted necks are more expensive due to the extra process they go through. That process also results in a certain amount of wood rejected due to wood checking and other issues resulting from torrification."Roasting" is the same process that produces charcoal.
It's worth noting that roasting embrittles the wood (it's the tradeoff). While the necks may be more stable in terms of changes due to humidity or temperature, they also lose strength in the roasting process. IOW, they can actually break more easily. The more they've been roasted, the more brittle they become. Taken to an end, they *become* charcoal, but the wood becomes unusable well before that.
Last edited: Nov 24, 2020