Real wood expands and contracts with humidity and seasonal changes. It always has, and it always will. When wood is painted, that movement does not stop. The paint goes along for the ride.

Where two pieces of wood meet at a joint, that small amount of seasonal movement can show up as a fine hairline at the painted seam. It looks like a small line. It often shows up in the first winter or two after install, when the heat is on and the air in the house is dry. In some homes it appears in summer instead, when the air is humid.

This is normal

A hairline at a painted joint is normal wood behavior. It is not a defect in the cabinets, and it is not a failure of the finish. Any solid wood painted cabinets, from any shop, will move a little with the seasons.

There is no way to completely stop real wood from moving. The only way to eliminate that movement would be to stop using real wood, and that is not what custom cabinetry is.

What to expect

You may see a hairline at a few joints, especially:

  • Where door rails meet door stiles
  • Where face frame pieces meet at corners
  • Where panels meet stiles on larger doors or end panels

These hairlines tend to come and go. They open slightly in the dry season and close back up when the air is more humid. They are part of how a painted wood cabinet lives in a real house.

For more on why marks and joint lines tend to show more on painted surfaces than on stained wood, see Why Wear Is Often More Noticeable on Painted Cabinets Than Stained Wood.

Keeping it minimal

You cannot eliminate wood movement, but you can keep it small by keeping the indoor humidity in a reasonable range. In the Chicago area, that usually means using a humidifier in the winter when the heat is on, and not over-drying the house. Most painted cabinets behave best when the air in the house stays somewhere in the 35 to 50 percent humidity range.

When to call us

If something looks different from a small hairline at a joint, give us a call. We are happy to take a look. Hairlines at joints are part of normal wood behavior. Other things may not be, and we would rather you ask than wonder.