I have had luck using a bit of liquid soap detergent in the tempera, but then again it depends on the tempera. The tempera I use was sax brand. I have had luck with it, but another brand I had bad luck with completely.
k-8 New Jersey
-------------- Original message --------------
> In a message dated 2/20/05 7:35:18 PM, firstname.lastname@example.org writes:
> << I used black tempera for the very same thing and was happy with the
> results. >>
> I have used black tempera and it turned brittle and flaked off...made a huge
> mess! ugh!