Why do I see lines at the joints of some cabinets?
Even though the best cabinet manufacturers use the highest grade materials and the most skilled workmanship, over time you may see visible joints – especially so on painted cabinet doors and face frames which are made of wood. This is because wood is subject to expansion and contraction. Cabinet doors and face frames on inset cabinets are constructed from solid hardwoods with frame joints and face frame miter joints. A degree of movement is to be expected based on variations in humidity and temperature, especially during seasonal changes. It is recommended that cabinets be stored and installed in an environment between 38 and 48 degrees. This type of “breathing” is characteristic and not considered a defect or cracking or splitting.
What are other options?
The expansion and contraction of these joints does not occur in doors which are made of one-piece solid composites such as MDF. MDF or medium density fiberboard is a composite material which is stable and does not expand or contract with humidity and temperature variations. MDF doors can be made as a slab with a wood veneer or composite glued to the face and sides, or the door can be made to closely resemble a traditional solid wood door style. However, an inset door is usually set into a face frame that would be made of solid wood so the joint movement might be evident over time. Typically an MDF door would be mounted on a frameless cabinet, but stiles could be added between cabinets to give the appearance of a partial inset.