CarolM5397 wrote:
>
> "How do you feel about calling both tempera and gouache "opaque
> watercolor" ?

TEMPERA: Originally a pigment ground with egg emulsion, properly called
egg tempera, that dries hard and quickly and is very permanent; while egg
tempera is still used, in general, the term refers to *goache*, poster
colors, and other *opaque watercolors*.  (Asterisks mine.)
   Elspass, Margy Lee (1984).  North Light Dictionary of Art Terms.
Cincinnati, OH : Writer's Digest Books.

The term "opaque watercolor," has been around a long time.  We were using
it over 35 years ago for the same purpose you describe, and we picked it
up from others before us.
T.