For the past decade, commercial printing
plate manufacturers and inkjet imaging
specialists have been working on an
effective system for imaging commercial
printing plates through some type of
inkjet printing device. A few polyester
devices with fairly limited quality capabilities
have been introduced over the years,
but their limitations have resulted in
these machines barely making a dent in
the overall computer-to-plate market.
Inkjet printing, meanwhile, has progressed
by leaps and bounds in the past
decade. The increasing quality of screening,
and decreasing size of dots have
been augmented by much higher speed
and much more durable printheads.
Now, the same advances in printer
technology that have been making your
life easier are allowing computer-to-plate
(CtP) technology to be accomplished
through conventional inkjet systems.
Both of the new products I discuss here
are built on conventional off-the-shelf
wide-format printers. They also use customized
versions of off-the-shelf RIPs.
JetPlate
Print Imaging Sciences, Inc. of Nashua,
NH, now named JetPlate (www.jetplate.
com), won a GATF technology award in
July 2002 with its JetPlate system, which
this magazine reported on at that time.
JetPlate is an affordable, desktop
metal CtP system for small offset
presses, based on an inexpensive B3-format
inkjet printer. While other CtP systems
use costly lasers, this system's
plates are imaged with innovative “liquid
light” ink, which reacts with the photosensitive
emulsion. “This inexpensive system,
with inexpensive consumables, ties
into other vendors' systems and brings
computer-to-plate technology to the
majority of our industry”?the small or
low-end printers,” a GATF judge
explained when making the
award.
At Drupa, the newly minted
company displayed its latest
releases and its new corporate
name, but the big news was the
interest being stimulated by the fact
that these machines can image highquality
conventional metal commercial
printing plates with up to 175 lpi-equivalent
resolution. This is being done with
some modifications to an off-the-shelf
inkjet printer using what the company
calls “liquid light,” a liquid applied using a
standard ink cartridge. This is a photosensitive
chemical that must be processed
through a standard plate processor. The
company includes a Harlequin RIP in its
package, which sells as low as $30,000
for a 2-up (JetPlate 4000) version; a 4-up
version (JetPlate 7600) is also available.
Glunz & Jensen iCtP
But Glunz & Jensen (www.glunzjensen.
com), well-known for its plate and
film processors for the commercial print
industry, has taken inkjet CtP a step further
with its iCtP system. This is a chemistry-
free solution, using only a relatively
cool (110″?) curing process and the only
“chemical” used is a finishing gum. The
imaging is also done on non-sensitized
plate material”?a considerably lessexpensive
solution. Since these units will
sell for about $35,000 (published reports
immediately after Drupa incorrectly
stated a $25,000 figure), the total cost
per plate produced is dramatically less
than conventional CtP.
The PlateWriter 4200 platesetter prototype
units used an FM screening algorithm
generated by a Harlequin-based
Xitron RIP, which the company reports is
giving them excellent quality. The FM
screening in the prototype is capable of
emulating 175 line conventional screening.
Hank Clifford, G&J's US VP for sales
and marketing, says the company also is
actively working on AM screening for the
device and has set that as a high priority.
Breakthrough technology
The chief problem that has delayed the
release of a high-quality metal imaging
device through inkjet technologies has
been in the screening process itself.
Recent developments, however, have
allowed manufacturers to develop much
greater control of dot size and shape to
avoid coarse screening and banding and
stepping issues. While printing on paper
has been more forgiving, and manufacturers
have effectively mitigated most of
those issues, imaging on metal had its
own set of issues that have been much
more difficult to solve. Early entries to utilize
CtP for plate marking have been done
with polyester plates that are largely used
in lower-quality commercial print.
To move to a commercial quality level
of imaging meant hitting the 175 lpi
mark, and that was a tough proposition.
Both JetPlate and Glunz & Jensen say
they have been able to hit that benchmark.
The samples printed at Drupa
seem to indicate to those who have seen
them that they have indeed made the
breakthrough that has escaped them for
so long. This writer did see a sample of a
G&J piece printed at Drupa, which gave
every appearance of having come off a
conventional laser CtP device.
Both companies also say the issues of
registration and repeatability have successfully
been dealt with.
Lowering the barriers
What is happening industry-wide is a further
blurring of the line between “copyshops,”
commercial printers, and wide-format
print providers. Commercial printers,
for instance, are buying digital presses
such as the HP Indigo and the Xerox 6060,
while copy shops are buying “direct imaging”
(DI) solutions like the KPG and Ryobi
DI presses.
Certainly, wide-format operations
would look askance at buying a $100,000
platesetter with a totally new front-end
computer system to step into the realm of
commercial print. But now the bar has
dropped a couple of notches”?the price of
admission has been cut by two-thirds.
And the technology itself is no longer foreign:
it's something the wide-format print
provider deals with every day.
Will these new CtP offerings entice
some companies who specialize in wide
format and similar graphics to cross
over the line? The device manufacturers
are orienting their marketing to small
commercial printers and larger copy
shops, but wide-format printers may not
want to wait and watch their competition
exploit a promising new technology that
they have a great deal of experience
with. These new products might well be
worth a look, if only to see where inkjet
technology is headed.