"The goal of board oil is to penetrate the wood and saturate the wood fibers, in order to stop any other liquids (blood, bacteria) and moisture from soaking into the board. As well, a well-oiled cutting board will keep the same shape when the wood fibers are saturated, so it will not expand and shrink compared to a board that is left to completely dry, then exposed to water. This shrinking and expanding effect is the main cause of warped cutting boards." ( https://www.cuttingboard.com/how-to-oil-and-maintain-a-cutting-board/)
