Multipurpose, ready-to-use, low VOC, synthetic resin-based primer with bond promoting silica aggregates suspended in a dispersion. It enhances the performance and adhesion of mortars to existing ceramics and difficult-to-bond-to substrates. Plus, it improves bonding of self-leveling underlayments (SLU's) and bonds of render coats over cementitious substrates. Suitable for a wide variety of substrates.