printing on plastic
Posted by
Elliot Burke
on 1999-06-10 22:07:20 UTC
Message: 6
Date: Tue, 8 Jun 1999 13:13:28 -0500
From: psp@... (Phil Plumbo)
Subject: Re: A sense of humor needs to be restored to these proceedings
"Elliot Burke" <elliot@...> writes:
The machine has accuracy down to the 6 micron level, per measurements by a
prof at Georgia Tech whose name I forget at the moment. We used the
machines to print patterns which were photoreduced to produce computer
generated hologram. They were reduced onto photoresist onto silica
substrates. Ion beam milling was used to make the pattern in the silica.
This was in a workshop, which made me wish for all that cool equipment he
had in the physics department basement.
The reason these machines need to be accurate is that if they aren't, they
won't work for their intended purpose, and graphics arts people bitch when
their separtions get weird banding effects...
direct download. For a project like this it would be preferable to avoid
page layout programs and code the scale directly in PostScript to avoid
pixel rounding errors, although if you run it at 3600 dpi the rounding error
may not be significant enough to matter. If line width is critical, note
that rounding errors can give rise to lines of different width as well as
+/- 1 pixel positioning errors.
My experience with postscript was rather unsatisfactory. This was on a Agfa
machine. While it superficially printed correctly, the machine applied some
sort of (antialiasing?) algorithm and spoiled the fine line patterns. The
ps file had been thoughly check out and was correct, yet the Agfa machine
didn't print exactly what was was in the file. Maybe a Linotronic brand
machine would work better. The tech support people at Agfa were
sympathetic, but not helpful. They could see the problem, but not explain
or fix it.
So you might have to try a couple of file formats to get what you want. I
went through three before the exporting of DXF to Pagemaker was tried, but
I'm sure with different machines things could be different. The postscript
interpretation software is sure to be different. As a matter of fact, the
same file which used to work as an EPS file on an old Agfa machine was the
one that didn't print right and had to be exported in my tortuous fashion.
A $8/print, it isn't a big hardship, unless you're under a time constraint.
It is important, as Phil noted above, to keep in mind the resolution of the
machine doing the printing. Imagine printing with point 1/3600 inch wide,
add up integral number of them to get the pattern you want.
You'll also want to print some test patterns to see what the dot size really
is, what happens when lines intersect at small angles, and whatever else
you might be interested in. Print the patterns at an angle to reduce
aliasing!! Important.
It might be that different sources of postscript files would succeed where
AutoCAD ps output failed.
Its worthwhile to download GhostScript to examine the files before you print
them.
installed with some sort of menu or autodetect system. Someone must be
doing this, Windows has had it for years, and Linux wouldn't want to seem to
be behind.
Elliot Burke
Date: Tue, 8 Jun 1999 13:13:28 -0500
From: psp@... (Phil Plumbo)
Subject: Re: A sense of humor needs to be restored to these proceedings
"Elliot Burke" <elliot@...> writes:
>Now on to getting patterns printed on plastic. Forgive me if this is tooAs I understand it, separation work is the primary use of these machines.
>elementary, but there may be some out there who don't know this trick. The
>trick is to use the Linotronic (type) film printer at a printing service.
>These print on mylar film very high contrast stable patterns. The machines
>have resolutions from between 1200 and 3600 dpi.
>A good idea, subject to the proviso that film recorders are not perfectly
>linear, and that high resolution alone is no guarantee of linearity and
>absolute accuracy. In my experience most low-end service bureau shop owners
>don't know the specifications of their machines, just whether or not it is
>adequate for their application. For precision work I recommend you find a
>service bureau that does specializes in quality color-separation work and
>image it at the highest resolution available, preferably 3600 dpi.
The machine has accuracy down to the 6 micron level, per measurements by a
prof at Georgia Tech whose name I forget at the moment. We used the
machines to print patterns which were photoreduced to produce computer
generated hologram. They were reduced onto photoresist onto silica
substrates. Ion beam milling was used to make the pattern in the silica.
This was in a workshop, which made me wish for all that cool equipment he
had in the physics department basement.
The reason these machines need to be accurate is that if they aren't, they
won't work for their intended purpose, and graphics arts people bitch when
their separtions get weird banding effects...
>They are used by Mac zealots, and only understand file formats that areThey all understand PostScript and will accept a PostScript text file for
>popular in the graphic arts world.
direct download. For a project like this it would be preferable to avoid
page layout programs and code the scale directly in PostScript to avoid
pixel rounding errors, although if you run it at 3600 dpi the rounding error
may not be significant enough to matter. If line width is critical, note
that rounding errors can give rise to lines of different width as well as
+/- 1 pixel positioning errors.
My experience with postscript was rather unsatisfactory. This was on a Agfa
machine. While it superficially printed correctly, the machine applied some
sort of (antialiasing?) algorithm and spoiled the fine line patterns. The
ps file had been thoughly check out and was correct, yet the Agfa machine
didn't print exactly what was was in the file. Maybe a Linotronic brand
machine would work better. The tech support people at Agfa were
sympathetic, but not helpful. They could see the problem, but not explain
or fix it.
So you might have to try a couple of file formats to get what you want. I
went through three before the exporting of DXF to Pagemaker was tried, but
I'm sure with different machines things could be different. The postscript
interpretation software is sure to be different. As a matter of fact, the
same file which used to work as an EPS file on an old Agfa machine was the
one that didn't print right and had to be exported in my tortuous fashion.
A $8/print, it isn't a big hardship, unless you're under a time constraint.
It is important, as Phil noted above, to keep in mind the resolution of the
machine doing the printing. Imagine printing with point 1/3600 inch wide,
add up integral number of them to get the pattern you want.
You'll also want to print some test patterns to see what the dot size really
is, what happens when lines intersect at small angles, and whatever else
you might be interested in. Print the patterns at an angle to reduce
aliasing!! Important.
It might be that different sources of postscript files would succeed where
AutoCAD ps output failed.
Its worthwhile to download GhostScript to examine the files before you print
them.
>Since the installation of Linux is very machine dependent, i.e., the set ofanother
>drivers installed on my machine may differ from the set installed on
>machine of different hardware makeup, I suspect it won't be possible, or atOK, everything but the machine dependent things automatic, and the rest
>least simple, in the near term.
installed with some sort of menu or autodetect system. Someone must be
doing this, Windows has had it for years, and Linux wouldn't want to seem to
be behind.
Elliot Burke