Are your boards stained or varnished?
No, none of the boards we sell are stained or varnished in any way. Doing so would make them unsafe for use with food. After production, we clean any residue or soot from the boards using a warm wet cloth, and then they are simply oiled with Grapeseed Oil or Mineral Oil before being dried and packed.
Colour differences in a board is not from oiling, but from a variation in the grain of the timber.