Tried the"heatless" toner transfer process
using what I could find at home, acetone and rubbing (isopropyl 70% by
volume) alcohol. Printed the PCB artwork on standard, white, office
paper. Using the 8:3 mix didn't get any transfer to the PCB. Upped the
ratio to 8 parts alcohol to 6 parts acetone. Did get a good transfer,
but some of the toner came off the board while trying to remove
(rubbing) the paper residue left when the paper was pealed off. This
was my second try to use the "heatless" toner transfer.
Some things to try is to let the alcohol-acetone saturated paper fully dry on the board (didn't let the paper fully dry the second attempt), let the paper soak in water longer before removing (may put some dish washing soap in the water). Will try to find a more concentrate alcohol to use (will have to adjust the alcohol acetone ratio with a higher alcohol concentrate).
This process looks promising enough to keep experimenting to come up with a mix, process that works for me."