Dried dressed timber is known as a more premium finish lumber, having one or more of its faces planed smooth. Treated lumber or pressure-treated lumber, is wood that’s been infused with preservatives to protect it from the elements including rot and insect damage. It can be stained, painted or left natural for a clean, simple look. They are lightweight, easy to nail, saw, trim or cut. Dimensions: 2 Inch x 4 Inch x 16 Foot.