About Smart Prime® Get the ultimate performance with our most advanced interior/exterior primer: Rust-Oleum® Zinsser® Smart Prime® Primer. This next-generation, low-VOC, water-based formula is the one primer you need for every professional or DIY project. Oil-base performance in an advanced water-base formula Primer for all projects Sticks to all surfaces – interior and exterior Blocks all stains, including water stains Low-VOC, low odor formula