Schmincke AQUA Fix Medium will make watercolour paints waterproof when they are dry. This is ideal when you are wanting to paint watercolours in layers as the colour underneath won't be re-activated and blend into the colour above.
It can be used to create amazing transparent watercolour effects. Use this medium directly with the paints instead of water. After use, clean brushes and palette with water and soap immediately.
Do not mix the AQUA Fix Medium directly into a half pan as it will make the water colour paint unusable when dry.