TWP 1500 Series Wood Stain and Preservative · Cedartone · 1-gallon The new TWP 1500 formula is designed to penetrate better, dry faster and outperform the previous formulae. TWP 1500 Series is an EPA registered wood preservative which prevents structural damage and wood decay on exterior above ground wood surfaces such as untreated or previously treated fencing, decking, wood siding, log homes and roofing. TWP 1500 Series resists water absorption that causes warping, cracking and splitting as well as preventing freeze damage in colder climates.TWP 1500 Series is higher in solids content which may result in "richer" colors than the 100 Series. In general the 1500 Series color will not match the colors in the 100.