When unstained wood is left outside, the sun and rain work together to decompose the wood. When rain seeps into the wood cells, it saturates them. The sun then dries out the cells and natural preservatives in the wood, which then makes it susceptible to wood rot and discolouration. UV protection in stain is a crucial component, protecting the lignin (which holds the wood fibres together) from breaking down. Transparent Iron Oxide pigments in the stain absorb UV radiation, while colour pigments enhance the appearance of your project. These pigments are highly durable, making them a great addition to the stain used to protect your wood. Since VOCs (Volatile Organic Compounds) have been taken out of many stains, the drying process has slowed down. UV rays act as an environmentally friendly way for stain to dry on wood.