How can I prevent the lifting of Gouache colours when mixing media?
Water resistance can be achieved by adding small amounts of Acrylic Matt Medium. Experimenting with a few colours will find the lowest level of medium required. The less acrylic in the gouache, the more like gouache it will remain. Care should be taken however as some colours can react. The pinks and violets in Designers Gouache can have a tendency to change colour on combination with acrylic. Some other Designers colours may be sensitive to alkali and produce gelatinous or lumpy mixtures. This reaction will be self evident whilst mixing on the palette. The addition of the medium will also deepen the tones and reduce the matt finish of the gouache colour.
