Torrefaction or thermal modification is a process where the tonewood is thermally treated with high temperature in oxygen controlled environment.
The results are soundboards with rich and vintage look. But the look is not all, the torrefied soundboards will produce that sweet sound that we all love. They will have richer dynamic range and fuller tone. Kind of like when you hear someone playing a vintage Martin guitar.
Last photo for comparison of torrefied and non-torrefied soundboards.
Take it calibrated.
This will be done accurately using a drum sander with 120grit sand paper.
