You could try what I do for UV film - tape the leading edge of the TRF to a piece of paper (carrier), so the paper holds the front edge flat and you can hold the back edge, feeding the pcb between the TRF and the paper. If you pull the two leading corners apart when you tape them, or tape the whole leading edge, that should prevent wrinkles.
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Re: [Homebrew_PCBs] Finally! A good toner transfer. On to etch.
2010-02-15 by DJ Delorie