This is when a piece of wood is cut in such a way that the long edge is not parallel to the natural growth line of the wood. Here, the grain lines are made to run diagonally or across the board. Plywood is one of the common examples of a cross grain wood utilized in the kitchen cabinet construction. One surprising fact is that some woodworkers see cross grain wood as a more durable and stronger alternative to solid wood which contracts and expands under the influence of weather factors such as temperature and humidity levels.
Staining and painting newly constructed cabinets don't prevent them these effects, and thus their shapes and dimensions can be altered. These changes can cause cabinets to develop weak spots that could eventually lead to broken joints, wood splits and cracks. Cross grain woods have more resistance to the negative effects caused by fluctuations in temperature and humidity and hence experiences less structural changes; a key reason why plywood is widely accepted as the construction material for cabinet substructures and frames.