Stainban® 187 is a zinc free, aqueous tannin stain inhibitor additive for water based primers intended for wood protection. The unique mechanism of the product allows it to effectively block tannins in stains and pigmented coatings. It can be easily incorporated at any stage of paint production and is compatible with a wide range of surfactant and dispersants. Stainban® 187 is effective at any PVC value of primers; however, it is more economical at higher PVC. It may reduce or eliminate the need for zinc oxide and stabilizing amines in primers. Paints made with Stainban® 187 have good storage stability and improved humidity resistance. It is HAPS free and does not contribute to VOC. Typical use level ranges from 1 – 3% based upon total formula weight.