Cellular PVC
It will never rot, cup, split, twist, or warp. It is impervious to moisture, salt, and insects. It's also suitable for ground or masonry contact and comes with a 25-year manufacturer's warranty. Cellular PVC has most of the good qualities of real wood but none of wood's maintenance requirements. Intended for use in non-stress and non-load bearing applications.
What is Cellular PVC?
Cellular PVC is the premier choice for synthetic wood. It has the look and feel of real wood. It's about the same density as White Pine, so it doesn't have that hard plastic sound when tapped nor is it cold to the touch. Items we cut from Cellular PVC have the same crisp corners as our wood items. There are no air bubbles or other voids and it's the same semi-matte white color throughout.
Looks like painted wood
If you want white it needs no painting. Unless you tell, no one will know it's not real wood that's been painted white. Indeed, some won't believe you even if you do tell! If you have another color in mind, use a 100% acrylic latex paint with a Light Reflective Value of 55 or higher. Cellular PVC does not absorb moisture so paint lasts much longer than on wood.