Polyurethane is designed to protect wood and give it a longer lifespan than if it were left in its natural finish. Whenever possible, it's always best to have a practice piece of wood available before applying to any finished work.
Transparency of Grain
The transparent coating of polyurethane allows the beauty of a wood project to show through.
When a wood piece is to be used for furniture, polyurethane will protect the surface from water stains or vapor.
Fungus and Mildew Resistant
In damp climates a coating of polyurethane can be used to protect wooden windows as well as other wood projects.
This coating helps protect wood from scratches and nicks.
A variety of finishes are available, from glossy to flat.