Wood is an organic material that contains a certain amount of wood constituents, such as tannic acid. These substances are water-soluble and can be transported from one layer to another, all the way to the surface, when water-based or wood paints are used. This does not happen with Isoprimer 243 or Hydro-PU-XSpray Isoprimer 2243 as the prime coat. Although they are both water-based, they provide reliable protection thanks to their cationic isolating effect. The special formula and slightly acidic pH value create an excellent barrier effect. Wood constituents therefore have no chance of reaching the surface of the top coats.