Homebrew PCBs

Just fabricated my first PCB today using the photolithography method; 
prior PCBs were made using the toner-transfer method.  My 10 to 15 
mil tracks were faithfully produced.  Experimented with 1 and 5 mil 
tracks and learned I could do 5 mils but not 1 mils.  I believe this 
limit is related to the resolution of the artwork I am using.  I draw 
the track pattern using AutoCAD. It is then printed onto laser-
printer transparency film (CG 3300 by 3M) using my HP LaserJet 2200d 
at 1200 dpi and 180 lpi.

When I examine the resulting transparency under a microscope, it 
becomes apparent the 1 mil line is poorly rendered.  At this time, I 
do not know if the limiting factor is the printer or the film.

Does anyone have any ideas/suggestions?  One possibility of course is 
to have the artwork transparency professionally made.

Lyman

--- In Homebrew_PCBs@yahoogroups.com, Richard <metal@...> wrote:
>
> 
> I will second David's comments on the photo process.
> 
> I too have been making boards, both 1 and 2 sided, since
> about 1980 using the photo process; and like David, I highly
> recommend it.
> 
> You can -easily- achieve 6-8 mil traces/spaces; unlike the
> toner-transfer method where you must use the greatest
> care to achieve a -clean and solid- 10 mils, let alone anything
> finer than that.
> 
> In fact, with some careful attention, you can achieve -2 mils-
> with a dryfilm/photo process; which you simply -cannot- do
> with toner transfer, no matter what.