They're sturdy, but require maintenance. Solid-core doors are made of particleboard or steel centers covered by wood or fiberglass veneer to give a durable finish. Hollow-core doors have cardboard baffle centers covered by veneer. They're inexpensive, and are used only inside. Solid wood or solid-core interior doors offer sound control properties and good looks.
Painting is an easy way to compliment a room's colors.
Staining a door allows the wood grain to be seen, giving the door character that usually provides more detail to the room. Matching stain to existing trim can be difficult, and some wood fillers used to cover nailheads don't stain well. Porous wood may require several applications, and once stained, changing your mind to switch colors and stripping the door can be a difficult process. All exterior doors are made to resist wear from the elements. A high quality wood door may outperform a cheap steel door, but there are some general differences.