When I do a board with Hot Toner Transfer I have always had better luck running the board through the Scotch laminator I use 3 times to preheat before I applied the paper. Then 4 more times , once in each direction to transfer the toner. There is information about using packing tape applied to printer paper as a transfer medium at TheRandomLab: DIY PCBs on the cheap: toner transfer with Box Packing Tape and a Hair Straightener / Iron
A few months ago I started to design an affordable 2WD Robot Kit to teach 20 students in a workshop in the AVM Master, at the Universidad Politécnica ...