This riser is finished with the same UV coating that our stair treads are finished with. Our skirtboard is also finished with the same UV coating and all of these products are designed to match each other. This finish is the same finish you'll find on nearly all brand name prefinished flooring and is very durable. We do warrant the finish and treads to be free of defects but we don't guarantee a life expectancy for the finish because that is a direct result of maintenance and cleaning. This finish, if kept relatively clean, should last 30-50 years before needing a recoat. The treads and risers will last a lifetime or longer (some homes have the same treads and flooring that was installed over a hundred years ago!)
For more information on our finish see:
http://www.stair-treads.com/diamond-coat-ii
For warranty information see:
http://www.stair-treads.com/warranty