Generally, purchase the best materials you can afford. You don’t need to purchase a tube of every color or have an arsenal of 30 or 40 brushes. It’s better to have a limited number of professional-quality paints and a few good brushes than a cache of lesser-quality tools.
TRANSPARENT & OPAQUE
Watercolors come in two types: transparent and opaque. Opaque watercolor is also known as gouache, which is similar to the tempera paint you used in school. Gouache contains white pigment mixed in with the color to allow the paint to cover with clean opacity. You can thin gouache and paint with it transparently, if you desire. ...