The TreeTop line is built using a very old techinque - solid wood joinery. Before plywood and screws, fine cabinetry was built using this building method. A great deal of craftsmenship is need to for this type of cabinetry. It was quite a project then as it is now. Instead of plywood, each cabinet part is a 5 piece panel just like a door. After all the parts are made, each piece is given a corresponding tongue or groove. The project is like an intricate jigsaw puzzle that once made, it can be held together without the need of glue or screws. It's truly an old, unique way of building fine cabinetry.