Homebrew PCBs

The white paper-like vellum also is what is used in the engraving 
industry for making the masks for sandblasting. At UV, it seems to be 
much more transparent than transparencies. Also, for a crisper image, 
put the printed side of the vellum closer to the reactive surface. It 
will create a much sharper transfer. Make sure you mirror your mask. :)

Chris

Steve wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>, KeepIt SimpleStupid
> <keepitsimplestupid@...> wrote:
> >
> >
> > --- Frank <frank@...> wrote:
> >
> > > Firstly, the blacks aren't very black, they're all
> > > splotchy. I
> > > wanted to use GCC Toner Density Spray, but according
>
> > You don't want to print on transparency film. Try to
> > find some polyester paper. It will do wonders for
> > printing. It's translucent, but not transparent, but
> > will expose with UV.
>
> Tshirt makers, when they print and expose their photosensitive
> screens, use "vellum" as you describe, not transparencies. Either with
> laser printers, or with inkjet printers.
>
> Here is a good board on screenprinting and such where you may find
> more info on these "vellums". I put that in quotes because real vellum
> was something like the inside layer of animal hide, modern vellum is
> cotton or polyester.
>
> http://boards.screenprinters.net/ <http://boards.screenprinters.net/>
>
> What looks the clearest is not always the best. I'm in EET training
> right now and have to make blueprints. I bought some fancy very clear
> vellum for drafting (pencil) and it -looks- like it would work better
> than the stock 100% cotton vellum they wanted us to buy. Their vellum
> is whiter and appears more opaque than what I bought. But the pencil
> lines are a lot darker on their vellum, so their vellum works better
> for blueprints.
>
> Steve Greenfield
>
>