Johnstone's Trade Aqua Undercoat is an innovative, water-based undercoat ideal for interior and exterior wood and metals. It looks, feels, and applies like a traditional undercoat but is quick-drying, reducing application time. Designed for use under Johnstone's Trade Aqua Water Based Gloss or Satin for best results, but also suitable for use under other water-based paints. It is a low odour, low VOC solution. For best results, apply to a clean, dry surface using a synthetic brush. Avoid overspreading.