This quadruple set of sliding doors is just part of an entire home full of white oak doors we built. They are large and had to be sequenced and center balanced on both sides. We constructed the doors with a high density light weight core, cross banded them to prevent telegraphing from the hardwood edges and faced them on both sides with Rift White Oak. One other thing that these doors have is what we call an invisable edge. What that intails is hiding the door skin edges with the finished solid door edge. This only works if you cross band both sides of the door trapping a T-moulded dimensional lumber edge with perpendicular grain. This application really looks good but it does take more time to do and that does add up to additional expense. The good thing is that our customers get to decide whether that look is important to them or not.