Small Cracks in Painted Cabinets: Understanding and Preventing This Issue

By: Jenny Cazares

Why do I see small cracks in my painted cabinets?

With changes in humidity, there is expansion and contraction in your cabinet. The effect of that expansion and contraction are cracks, which show up in the joints, where the pieces of wood come together. 

These cracks are more likely to be seen (or noticed) on a painted cabinet, than a cabinet with a wood finish. A cabinet with a wood finish has more “activity” in the door or drawer front; although the cracks are still there, they are less noticeable.

In the cabinet industry, these hairline cracks are referred to as “witness lines”. These witness lines are not considered “defects”, nor do they affect the integrity of your cabinet doors, drawers, or cabinet boxes. They are normal; you may see them at some point during the life of your cabinets. 

If you do see these witness lines, they should be very thin, and the paint should not be chipping or peeling off. It should just be a separation of the wood and the paint, where the pieces of wood are joined together.  

Where might I see witness lines?

You may find witness lines:

• Where the stiles and rails of your doors or drawer fronts come together.

• Where the center panel of a door, or drawer front, meets the stiles and rails.

• On the edges of the cabinets, or in the corners where your cabinets are joined together.

What are stiles and rails?

Stiles are the vertical pieces of your cabinet doors and drawer fronts. Rails are the horizontal pieces (think of a railroad that “runs” horizontally”). 

What is the cause of my cabinet paint cracks?

Humidity is the culprit. You may or may not see witness lines in your cabinet. It is difficult to know for sure until you see it. Wood is a natural product; it will adjust to life in your home over time.

How is a door or drawer front created? 

A door or drawer front that has four pieces of wood joined together, with a panel in the center (not a slab style door) is created by joining rails and stiles together, along with a center panel. The center panel is typically made from wood or MDF (medium-density fiberboard). 

What is MDF?

The MDF that is used in premium cabinetry is not the same MDF with which you may be familiar. It is a stronger, denser board, is easier to cut, takes paint better than wood, and is more dent and impact resistant than wood. 

Will a wood center panel show more cracks in my painted cabinets than an MDF panel?

Wood center panels are more likely to expand and contract due to their organic nature. Since MDF is not wood, it will not expand and contract. You are less likely to see cracks where the MDF panel meets the rails and stiles than with a wood panel. 

It is standard in the cabinet industry to use MDF center panels with painted cabinetry. The reason is to prevent expansion and contraction, thereby reducing the possibility of witness lines in your cabinetry. This is the preferred method of construction.  

Can I keep my cabinets from cracking?

It would be a challenge for anyone to control the humidity in their home year-round. 

In the winter, heat dries out the air and causes wood to shrink. Using a humidifier will help control the humidity.

In the summer, you may have more humidity in the air in your home. You can use a dehumidifier to remove excess moisture in the air.

Neither of these options are foolproof. Witness lines can be difficult to prevent.

How do I maintain my cabinets that might show witness lines over time?

Most cabinet providers will give you a touch-up kit at the time of installation. If you have a custom color, it is recommended to save some of the paint that was used for your project. 

Sherwin Williams can match any paint color from your phone. If you don’t have some of the original paint used on your cabinets, the best color match would be achieved from bringing a cabinet door or drawer front to the paint store, to have them create a custom match.

Due to the fact that “witness lines” are not a defect, a homeowner would maintain them as needed. 

If you don’t feel comfortable with touching up your cabinets, you can hire a painter, for a reasonable price, for small touch-up jobs.

Unfortunately, there is not a solution that is fail-proof for preventing any painted cabinet from showing witness lines. They may return from time to time over the years. 

If you’d like tricks and tips on keeping your cabinets looking great, feel free to visit our website.

Talk to your cabinet partner about the best cabinet options for your project. Also ask about what you can expect regarding witness lines when purchasing painted cabinets from your provider. Your cabinet partner should be happy and willing to talk with you about the possibility of witness lines over the lifetime of your cabinets. They should be able to show you what they may look like, what is acceptable, and what is not acceptable.