Not long ago, the only real choice for creating a pad printing cliché was to
chemically etch a steel plate. However, new innovations and advancements with
photopolymer technology and laser-based CTP systems have created more choices
for pad printing operations to consider.
Steel clichés for pad printing continue to be the mainstay for very large
runs, especially for automotive, medical, or consumer electronic applications.
Steel clichés are chemically etched and are available in either 10 mm (3/8”) or
0.5 mm (0.02) thickness. Thinner plates are used for runs up to 500,000 and the
thicker plates are most commonly used for runs over 500,000.
The number one advantage of properly manufactured steel clichés is that they
can last as long as one million impressions or more. Again, this can be
important for very long runs, where eliminating machine downtime to change out
the cliché can make a substantial difference in production efficiency.
The disadvantage of steel clichés is the high cost and extended lead times to
manufacture them. Because steel clichés are chemically etched, most are not
manufactured in-house and are created by a supplier specializing in this
service. In addition, the chemicals create an environmental issue to consider.
However, it is important to keep in mind that the most common applications for
steel clichés involve very large runs where pre-planning is necessary so lead
times and overall costs are not main factors.
Laser-etched Computer-to-plate Systems
Computer-to-plate (CTP) laser systems are the newest technology on the market
for creating pad printing clichés. “This technology provides a great advantage
for pad printing companies who want to improve efficiencies, reduce plate making
time, and standardize the pad printing process,” stated Ben Adner, president of
Inkcups Now. “It can be an excellent choice for manufacturing clichés for both
short-run and long-run applications.”
Many potential advantages exist when considering a CTP laser system. Because
it is computer-to-plate, graphics are first generation, with no loss of
resolution – unlike photopolymer or steel clichés where film is first needed to
create the image. There are no film, developing, or etching material costs. And,
a main advantage is time. Laser-etched clichés can be made in three to five
The disadvantage of a CTP laser system is the upfront costs involved with
setting up the system. A laser etching system can run several times the cost of
setting up photopolymer cliché exposure, development, and post-exposure/drying
equipment. Another issue to consider is that it is imperative to have a capable
operator to laser-etch the clichés. Although the software is not overly
difficult to understand, knowledge in the area of computer graphic software is
necessary to properly create laser-etched plates. “The key to creating
consistent, laser-etched clichés is having proper training and a good operator
running the system,” stated Michael Chaney, vice president of Diversified
Printing Techniques. “It is important that the supplier of the laser system
provides training and service at the time of purchase.”
YAG laser systems were the first generation of CTP laser systems on the
market and are more expensive systems. However, one large advantage of a YAG
laser system is the potential ability to perform industrial laser marking as
well. There are now C02-based laser plate making systems that have been recently
introduced which sell for as little as $10,000 - $25,000. With these new
systems, the start-up cost can be much more affordable.
YAG laser technology uses aluminun-based plates
while the newer C02 laser plates are made of a steel-backed coated
When using the YAG laser technology, aluminum-based plates are used. The
advantage of the aluminum plates is that they are double-sided, so an image can
be etched in both sides of the plate. However, they are non-magnetic, so
additional sub-plates are typically used to properly seal the magnetic cup with
the plate. The CO2 system plates are a steel-backed coated plate made of a
special polymer. This provides the ability for the cliché to work with magnetic
ink cups and provides a more durable plate.
A growing trend in pad printing is to utilize photopolymer clichés exclusively
instead of metal clichés. “Many of the European pad print machine manufacturers
have almost totally gone to using photopolymer clichés,” stated Innovative
Marking Systems National Sales Manager John Kaverman. “Cost of manufacturing,
environmental ramifications, and overall costs have all contributed to this
Photopolymer clichés are an excellent choice for short to medium-sized runs –
from several hundred to several thousand. The advantage to photopolymer is the
relatively low cost and ability to have the clichés produced in-house with a
relatively small investment. Quality images can be produced by using a film
positive where the image is exposed and developed with a water or alcohol wash.
Several types of photopolymer cliché materials exist. There are single exposure
materials that are only exposed once, using the image film; and there are double
exposure materials that are exposed once with the image film, and a second time
with a line screen film. Additionally, there are water wash and alcohol wash
clichés, and different levels of quality are available in all the types. The key
is to find the right combination of price and quality for the specific
Photopolymer clichés can be produced at a
relatively low cost with a small investment to manufacture in-house.
The drawback to photopolymer clichés is their overall durability. They are
wonderful for short to medium-sized runs, but would not be the best choice for
runs of hundreds of thousands or over a million. The other concern with
photopolymer clichés is the number of steps involved in producing a plate. The
more steps involved, the more opportunity for error and for producing a low
quality cliché. As with laser-etched clichés, having the proper training and
equipment is essential in producing consistent, quality clichés.
Before choosing the type of cliché for a particular application, contact your
supplier and explain the types of work and images you are printing. For example,
is the image small with a lot of detail, large with bold areas, or a combination
of fine detail and large, bold areas? Also, sending samples of the artwork you
are working with is recommended. Finally, discuss with your supplier the run
lengths and turnaround times under which you most commonly are working. All of
these questions and scenarios can help determine which type of cliché and/or
processing equipment is best suited for your operation. In addition, if you are
considering manufacturing clichés in-house, either laser-etched or photopolymer,
make sure that proper training and service is available from the supplier. This
will help ensure quality clichés no matter what process is used.
As technology continues to grow and processes are perfected, what might be
the best choice for manufacturing your clichés at present may not be the best
choice two years from now. Therefore, it is wise to keep a continual pulse on
what is happening with cliché manufacturing – today and in the future.