To be the best you have to install the best. Synthetic felt paper cost triple the amount of tar paper, but it will never decay. And it has dog prints on it!
Artificially manufactured from polypropylene, fiberglass, polyethylene and polyester. They are light materials that are placed under the roofing shingles, offering a lighter, water and radiation resistant barrier for the roof deck. The materials make for a more efficient water barrier without the factoring of mass, meaning that the sheets are significantly thinner and lighter compared to felt paper roofing underlayment