Just thought I would share my home made toner transfer PCB results with you, using a Brother laser printer.
So I've done a bunch of tests with different paper, and the best paper for the job I found was this yellow stuff off of ebay: http://ebay.to/1V9jXQ4
It took a couple tries to get the toner to stick to it, but in the end I got it to work by taping a piece of it to another piece of plan paper with kapton tape and then running it through the printer. Like this:
I use a pretty standard way of transferring the toner to the PCB. I just tape down the toner transfer paper to the PCB, put a paper towel over it, and iron it on (two minutes seems to work good). After the two minutes, I spray the towel and PCB with water and iron it out – I repeat that for about one minute.
After that, I let the PCB cool and wash off the toner paper in a stream of water.
For etching I use strait ferric chloride in a squarish plastic container. It usually takes about 20 minutes to etch if a agitate the container every now and then, or less if I rub the ferric chloride on the board:
I then rinse off the board in cold water, and remove the toner with lacquer thinner.
And that's all!
Here's a finished test board:
(The first trace on the top-left is 2 mil, and the next one is 4 mil)
With this method I have reliably got down to 4 mil traces - I did get a 2 mil trace, but it was starting to have higher resistance (I wouldn't trust it at all)...
Yes, I got the idea for the test board from Steve - Thanks Steve!!