I've been reading a some threads about toner transfer for fine pitch SMT and
printing on metal foil. I tried it in my Epson Action Laser II, and it
worked good!

Getting a SMOOTH piece of Al (Aluminum) foil, I folded it over a piece of
paper and fed it into the manual paper feed slot. I took care that no
wrinkles would scratch the drum! The transfer and fusing worked great!
Unlike others results (dirty foil maybe?) the toner did not rub off. Inspite
of the fact that, logicaly, it shouldn't work.

The significance of this is:
1. Print a reverse circuit image (toner around trace) on the foil.

2. Copper plate the aluminum foil. Very cheap, fast & simple (if not dirty)

3.With adhesive, glue the foil to a substrate. No doubt the hard part.
I'm thinking of perfboard (I hate drilling!) Mylar (MULTILAYER BOARDS!!!
Tooo coool!) or shitty old G10.

4. Etch the aluminum off, resulting in copper traces remaing behind.

No more expensive Mylar sheets & half transfered ironed toner. But best yet,
by using multiple sheets, you might be able to do decent multi-layer boards.
Via's would be made by punching holes before laminating the foil to the
plastic. Copper traces extend over the hole, which would get filled with
solder paste. I can't wait to try it!

But don't blame me if you mess up your toner drum, I bet Al foil will
scratch it up real good. And a neg. image will use lots of toner. But should
still be far cheaper, easier, and more powerfull than current iron on crap,
which never worked well for me.