DIY pcb's

One other idea. What if a flatbed XY plotter pen assembly was replaced with an inkjet head containing etch resistant ink ?
Other problems would still remain though.

if you have a XY plotter with good resolution then it's just up to the ink, you could use some ink that is not washable, like the one in permanent markers wich can be cleaned by alchool or other stuff. i used to draw my pcb's with marker and the ink is resistent to the chemicals, but some markers have ink that is much stronger and can not be cleaned with alchool, and you need special paint cleaner. but that is the best i used.
but it would be even better if you could modify a laser printer ans directly print with resistent inl on the pcb.....imagine how simple it would be!!

the pcb would have to be absolutely flat for the laser printer to print on to the board. Unfortunately most pcbs are not. This is the biggest advantage of the toner transfer method. Even if the pcb is not flat you will still get a properly etched pcb if the transfer was done correctly. I'll stick to the toner transfer method for now.

I found press and peel to be a disaster - expensive, poor resolution and does not work.

Stick with optical - laser on to a transparency.

What if an flatbed XY penplotter was designed from scratch to plot onto a copper laminate with etch resistant ink ? How different would this be from modifying an existing XY plotter ? Any ideas ?

You will need an etch-resistant ink. Also the distance of plotter pen from flat-bed surface should be increased to fit copper clad in between.

I know. Dont any manufacturers make such items. I think there would be
quite a market. I could be wrong though. A XY pen plotter designed for
the job would be very simple. It would have to plot in one color only.
Two colors if you want to do the silkscreen also. Any thoughts ?