I think you will run into difficulties with light
refraction as well as registration problems by trying
to layer up film. With layers light can sneak around
the toner because the toner is sitting on top of the
film. The more layers, the more trouble. With one
layer, you can expose with the toner or emulsion side
against the plate to avoid this. Success will mostly
depend on how complex the image is. If it is a big
blocky image, you should be OK. If it has much detail,
you will run into problems. I have found that it is
worth the money for service bureau output, especially
on a detailed piece where picking up fine lines is
important. I have heard that certain inkjets have a
dense enough black to work, but I don't have one and
have not experimented with inkjet output. Laser
printer output is pretty weak, as you have already
discovered. If you are working with any detail like
small type, multiple layers would be impossible to
register well enough, plus not worth wasting plate
material figuring out the correct exposure time. If
you have good consistent film output, the exposure
time is more predictable. Then there's the resolution
issue. The finer the detail, the more important it is
to use a higher resolution output device. Then there's
the splatter (I don't know the technical term for what
happens when the toner hits the film and
splats--causing tiny spurs), but it happens with laser
output and not with photographic film output such as
Linotronic. I don't know about inkjet on this issue.
But, it comes down to being all about the detail and
how much you want to keep.
--- chuck sumner <spam@...
> hi all,
> ive been doing some searching on google and in the
> letpress archives for
> some high level overview of how to make polymer
> plates, and havent found
> what im looking for, so i pose it here to the
> ive done a lot of silk screening over the years, and
> the way ive created
> my positives is by laser printing onto
> transparencies. this wont produce a
> solid enough fill, so i usually have to print three,
> along with alignment
> marks. ive gotten pretty good at lining them up and
> taping the together by
> cutting off progressively larger corners in a
> pyramid type layout. I then
> place them on the emulsion with a piece of glass on
> top to keep them flat.
> the emulsion i use allows me to burn a screen with a
> 150 watt flood bulb
> in 5 minutes like this.
> so what im wondering is this: can i use the same
> multiple laser printed
> positive strategy to make polymer plates? i wonder
> if anyone has had any
> experience making plates like this, or if it would
> even be possible. do
> you have to use uv light to expose the plates?
> i was going to just call na graphics, but this way
> others can possibly
> benefit also.
Do you Yahoo!?
SBC Yahoo! DSL - Now only $29.95 per month!