I studied Photogravure with Deli Sacilotto and he introduced me to copier
toner as an aquatint. ( It works well as a tusche wash in lithography too).
Originally, I learned to dust the copper plate with toner in the same manner
that etchers normally dust plates with rosin or asphaltum. before adhering
the tissue and developing, etching, etc. Recently, I have been dusting my
plates AFTER adhering the exposed tissue to the copper and drying at least
over night. The advantages here are that the tissue sticks much better to a
clean smooth(unaquatinted) surface, so there is less danger of pin holes and
lifting. Secondly, if your aquatint doesn't look perfect, or there is a big
blob in the middle, it is easy to brush off dry toner and dry polish the
plate with a soft cloth and aquatint again. As far as "fixing " the toner to
the plate, I am fortunate to have a stove with oven in my studio ( former
apartment) so I "fix" my copier toner aquatints in the oven set at 300
degrees and they get even heat all around. I watch the plate pretty carefully
and when the toner gets shiny looking,I know the toner will stick. One time
I did forget the plate in the oven for about an hour, and predictably, the
tissue had curled up and died. Another advantage with toner over rosin, YOU
CAN SEE IT! I usually give my plates a 50% or even less coverage of the
toner and the results are sublime- no dot pattern. Good luck, Janet Flohr,
Hare and Hound Press