All-Purpose Primer for Self-Leveling Underlayments Primer T is a low-VOC, magenta-colored, water-based acrylic primer that enhances the performance and adhesion of self-leveling underlayments (SLUs) on nonporous and porous substrates. Suitable for a wide variety of substrates, Primer T combines excellent versatility with easy, low-odor application. One-component, versatile primer for a wide variety of substrate conditions Single-coat application for faster turnaround and lower installation costs Easy handling and application Magenta-colored for easier coverage control