Why Wood Movement Matters (and How to Avoid Cracks and Warping)

If you’ve ever made a cutting board or knife handle that looked perfect one day and slightly bowed the next, you’ve experienced wood movement. Even experienced woodworkers get caught off guard by it. Wood is a natural material, and even after it’s been cut, milled, and sanded, it still responds to humidity and temperature changes.

The trick to avoiding problems is to understand that wood expands across the grain and barely moves along the grain. That means wide boards or wider glue-ups—like cutting boards—are the most vulnerable. When humidity rises, boards can swell, and if the pieces were too wet or glued incorrectly, they can warp or crack.

The best way to avoid this is to make sure your stock is properly dried and allowed to acclimate before you begin working. If you buy precision-milled cutting board strips, for example, they’ve already been surfaced, dimensioned, and dried to a stable moisture range. It helps to let them sit in your shop for a day or two before glue-ups so everything adjusts to the same conditions.

Once your project is assembled, a good finish seals out swings in humidity. For cutting boards, a food-safe oil or oil/wax blend will help slow moisture absorption. For knife scales and pens, hard film finishes like CA or polyurethane create strong protection.

Wood movement isn’t something to fear—it’s simply something to plan for. When you treat wood as a living material instead of a static one, your projects last longer, look better, and perform beautifully for years.