Hardwood Finishes
Aluminum Oxide Finish

More and more companies are turning to aluminum oxide finishes for their toughness and abrasion resistance. Like the ceramic finishes, this finish is usually much tougher than urethane and acrylic finishes which gives an easy to maintain floor for high traffic areas.
Ceramic Finish
Recently, the same ceramic finishes used for tile have been offered for wood flooring. They offer incredible abrasion wear resistance. With this finish, a floor is more resistant to stains, scratches and other imperfections.
Polyurethane Finish

Until recently, polyurethane was the most commonly applied finish. But despite new advances in durability, polyurethane is still considered a very good finish that can be stained to give it even more versatility. Maintenance is reasonably easy and while spot repairs can be done, they're usually easy to see.
Acrylic Impregnated Floor
The finish is forced into the floor itself to create a finish that goes all the way through the wear surface. It is frequently used in commercial projects, because it is so tough. Currently, only oak and maple are offered using this technique. Maintenance is easy and small scratches are easy to fix with a spray finish that makes them disappear completely. One negative is that water can leave permanent spots if allowed to dry on the surface.