> Sorry, this is slightly off topic.

Not if you're making PCB's for PICs.

> BTW have you tried to make a layout mask using
> transparency, ink jet printer and photoresist, is the quality and
> contrast acceptable? I have tried using laser printer, but have
> found that the black areas were slightly transparent to UV,

I have had very good luck with a Lexmark laser printer, printing
directly on clear mylar, and then using this to make a photoreversed
image using a Kepro photoreversing kit.

This is probably the reason I get good results.  The reversed image
is of good quality, and this is used to  mask the photoresist
on a copper board.  I have changed the default setup in the
laserprinter's menu to use the most ink available.  If you are using
some kind of econo-mode or ink saving mode you will probably have bad
results.

I have seen plotters that use a special pen to directly draw
photoetch on bare copper.  All it takes is a flatbed plotter, 8-1/2"
x 11".

> I also had no lack using this
> special transparencies (TES or something else) which you iron press
> on a copper board.

Iron-on's are great for making a professional looking front panel, or
for the silkscreen layer on the PCB, but are poor for laying out
copper.  I think they are great for hobbyists that don't have access
to a UV light or a darkroom.  If you try to do fine traces with iron
on's you are wasting your time.

Best Regards,

Lawrence Lile