Porter's Tannin Check has been designed to be used as a pre-treatment to inhibit tannin migration through water based paint systems. Particularly recommended prior to the application of Porter's Clearcote or Porter's Perfect Floor Paint on tannin rich timber. Also suitable to use after the application of Porter's Wood Wash prior to clear coating. This product contains 53g/L VOC. The APAS target level for this product is 450g/L. (APAS is the Australian Paint Approval Scheme).