I found the waxy paper backing from self adhesive labels worked well with my processes using a 600 dpi HP 6MP Laserjet but when I went to a 1200 dpi Oki to reduce poly pour porosity there was too much or the wrong sort of toner and the transfer smudged terribly.
Been experimenting with more porous papers, the transfer works well but removing the paper is problematic unless you soak it off. Then you have to be careful that there's no remnants or film from the paper left behind that can bugger the etch.
Experiment lots and when you find what works for you, stock up on the paper and share your process with a detailed description to help others along the same path.