I think Wirt has given a fair and even handed description of how forms
packages and printers work.  I would quibble with a couple of small
points however :).

I don't believe the "range of creatable forms is signifigantly greater"
for Postscript over PCL.  I'm afraid I also don't believe that the
"quality of output is significantly (to greatly) better".  These
statements may have been true in the dim and distant past, but I'm
afraid that the output from today's PostScript and PCL printer languages
are very close to being equivalent.  PCL functions at a lower level so
it forces a bit more work to be done by the creator of the print stream,
but the benefit is that it tends to print faster.  Postscript is a
higher level language, so it allows the creator of the print stream to
specify what they want in fewer commands, but at the cost of making the
printer work a little harder (making things print a little slower).

Today most desktop printers ship with both interpreters.  Both
interpreters use the same mechanical print engine so the quality of
print is pretty much the same.  If memory serves, Postscript has better
greyscale granularity but this is really only significant when printing
graduated greyscale images (e.g. B&W photographs) and doesn't really
apply to most forms.  Postscript also has some operators that allow you
to perform interesting transformations on the image that you're
rendering, but once again, this is more applicable to desktop publishing
than forms design.

I think there are far more important considerations when choosing a
printer.  Things such as price, speed, duty cycle, paper handling
capabilities, footprint etc.  In all likelyhood you'll be buying more
printers than forms packages, you may find letting your printer dictate
your forms package is more cost effective than letting your forms
package dictate your printer choice.

For the record: I'm assuming Wirt is comparing PCL5 with Postscript
Level 2.  PCL 6 contains the interesting transformations and improved
greyscales that are in Postscript Level 2 but is not yet widely
supported outside the desktop.

<plug>
Of course, by now, you're thinking I'm a PCL bigot.  This is untrue, in
fact the package I work on (JetForm Central) supports both PCL (both 5 &
6) and Postscript (Level 1 & 2) in addition to a number of label
printers.  We like to let the customer decide which printer they want
:).

JetForm produces both Fantasia (HP3000 specific functionality - PCL only
printing) and JetForm Central (cross-platform - multiple printer support
but no HP3000 specific features).  Both fall into the "create
intermediate data file and then merge with the form" category of forms
packages.
</plug>

I hope this helps,

Rob
=======================================================
Rob McDougall            Phone:  (613)751-4800 ext.5232
JetForm Corporation      Fax:    (613)751-4864
http://www.jetform.com   mailto:[log in to unmask]
=======================================================

-----Original Message-----

Date:    Tue, 7 Apr 1998 22:10:47 EDT
From:    WirtAtmar <[log in to unmask]>
Subject: Re: FW: forms packages <plug> for QueryCalc

[Snip]

In contrast, QueryCalc uses PostScript as its print language, thus the
range
of creatable forms is significantly greater (at significantly less
computational expense). Secondly, because QueryCalc is a report writer,
integration of the data into the form is done in the report writer
itself, so
there's only one stream of data emitted to the printer (no auxiliary
environment files, no field tags, etc.).

The downside to this second approach is that the printers have to be
PostScript-capable -- and the printers won't be as fast at rendering the
images as an equivalent PCL engine, when compared apples to apples. But
the
quality of output is significantly (to greatly) better. But perhaps most
importantly, the reliability and simplicity of the printing process are
greatly increased in the second approach.

Wirt Atmar

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