Q: I don’t know which white to use in my watercolors. How do you choose the right white?
A: Many traditional watercolorists will say the only white
that should appear in a watercolor painting is the color of the
paper—either untouched by the brush or showing through the layers of
applied paint. With this method, a color is tinted strictly by diluting
the amount of pigment applied to the paper. However, if you prefer to
lighten areas of a painting by applying white, or by mixing a lighter
shade of a tube color, the rule of thumb is to use Chinese white for
mixing and titanium white for covering. The reason is thus: titanium
white is a more opaque pigment and better suited for adding just a few
light highlights to a nearly finished painting, while Chinese white is
made with zinc oxide and is therefore more transparent.
Q: Is there any problem with using acrylic white for highlights, snowflakes, etc. on a watercolor?
A: White acrylic paint will adhere well to watercolor paper,
but many watercolorists choose to use white gouache instead. The
reasons vary. Gouache may be diluted with little effect on its ability
to adhere to a surface, while acrylic paint is not as reliable when
highly diluted. Another consideration is that some watercolor
associations and competitions require that participating artists use
only transparent pigments--the white of the paper is the only white