74 Karat
Digital offset in format 52 x 74 cm with high-end quality, flexibility and performance
With the 74 Karat digital sheetfed
offset press, KBA is dictating the
trends in the fast-growing 52 x 74 cm
market segment with respect to innovation,
integrated production, print quality,
ease of operation and net product
performance. The 74 Karat is a sheetfed offset press
with integrated digital plate imaging
for four-colour printing in the short to
medium-run sector.
74 Karat
Tight deadlines, increased
target group orientation and
pricing pressure, paired with demands
for maximum possible quality, are characteristic
of this market. With the aid
of the 74 Karat, job spectrums can be
expanded to cover new formats and materials
and to implement the outstanding
quality of offset print. Users from
the most varied backgrounds are thus
able to serve an enlarged customer
base with fast and optimally suited digital
printing technology.
The optional
integrated coating unit cuts drying
times and opens up new avenues for
product refinement which other DI
presses are unable to match. Modern,
practice-oriented workflows and new
applications, such as printing on films and plastics with oxidative-drying inks,
offer broad scope for individual customer
services and for differentiation
on fiercely contested markets.
It is not without reason that more and
more prepress studios, printing companies
with digital prepress and digital
service providers are putting their
money on the 74 Karat.
It would be out pleasure to welcome
you, too, to our market-oriented digital
world.
The 12-tonne 74 Karat, as a high-tech
press for waterless digital offset, is
characterised by its extremely compact
design and minimal space requirements.
The double-size plate
cylinders, the four Gravuflow™ shorttrain
inking units and the two imaging
units are arranged vertically to
the side of the central triple-sized
impression cylinder.
One-man operation
Whether with or without coating unit, the 74 Karat is designed for efficient and cost-effective one-man operation. The inking and printing units are located on one side of the press, while the feeder and delivery are positioned together at the other side. Practically all functions can be controlled directly from the operating console at the delivery. The ink cartridges can be exchanged quickly to allow simple, clean replacement of the ink even while the press is running, thus reducing cleaning and waste to a minimum.
Whether with or without coating unit, the 74 Karat is designed for efficient and cost-effective one-man operation. The inking and printing units are located on one side of the press, while the feeder and delivery are positioned together at the other side. Practically all functions can be controlled directly from the operating console at the delivery. The ink cartridges can be exchanged quickly to allow simple, clean replacement of the ink even while the press is running, thus reducing cleaning and waste to a minimum.
Fully automatic plate changingl
The 74 Karat uses waterless PEARLdry plates from Presstek. These plates are inserted into the plate changer in two books of 20 plates each, which is sufficient for 10 jobs. The plates are changed fully automatically. The used plates are unloaded and dropped into an ejection tray before the new plates are drawn in. The next job can then be started with a bare minimum of delay.
The 74 Karat uses waterless PEARLdry plates from Presstek. These plates are inserted into the plate changer in two books of 20 plates each, which is sufficient for 10 jobs. The plates are changed fully automatically. The used plates are unloaded and dropped into an ejection tray before the new plates are drawn in. The next job can then be started with a bare minimum of delay.
1. Impression cylinder: comprises three segments and gripper
systems, whereby each sheet remains in
the grippers for two cylinder rotations
2. Two imaging heads: (one head for each plate cylinder) allows the simultaneous imaging of all
four colour separations
3. Blanket cylinders:
with two blankets each
4. Plate cylinders:
each divided into two segments, with
auxiliary drives for high-speed imaging
while the machine itself is at standstill
5. Patented, keyless Gravuflow™
inking units:
comprising just two rollers – ink forme
roller and Gravuflow™ anilox roller – for
constant full inking of the plate
6. Fully automatic plate changer:
for loading and unloading of the plates
7. Ink cartridges: for clean and simple ink changes
8. Feeder and delivery on the same
side of the press: makes work much easier during one-man operation
9. Stream feeder with front and
side lays: guarantees accurate feed register and
high substrate flexibility
10. Delivery: with suction roller and control fans, as
well as a high-performance powder
sprayer
11. Coating unit (optional):
for inline finishing with dispersion
varnishes
12. IR/hot-air dryer (optional):
for fast drying
- Colour and register stability
- within each individual print
- over an entire print run
- from run to run
- from 74 Karat to 74 Karat worldwide
- from the 10th sheet onwards
- Top "high-end" offset quality
- Waterless offset – brilliant colour, sharp dots
- Soft reproduction of the finest gradations (2 to 98%)
- No ghosting
- Superb solids
- Integrated coating unit (optional)
- Dispersion varnishing for almost immediate backing-up, product refinement and faster finishing or conversion
- Standardised printing process
- Solid densities and tone reproduction to ISO 12647-1/2/3
- Colour management (match-the-proof)
- Repetitive accuracy
- Cost-effective high quality offset printing
- For runs of 500 to 10,000 sheets
- Fast job throughput, from RIP to production printing approx. 17 min. (job-dependent)
- Start-up waste until the first saleable sheet max. 10 sheets
- One operator for CTPress and printing
- Remote print & proof
- All-digital data transfer
- Distribute then print – print on demand
- Spatial independence of prepress and press
- Transfer of job data, substrate and image-dependent characteristics, register settings and colour-space profiles
Subject to technical modifications
Precise sheet infeed
The high-performance stream feeder of the 74 Karat supplies the sheets in exact timing. Front and side lays then provide for accurate alignment before the sheets are picked up by the swing grippers and passed in precise register to the impression cylinder.
The high-performance stream feeder of the 74 Karat supplies the sheets in exact timing. Front and side lays then provide for accurate alignment before the sheets are picked up by the swing grippers and passed in precise register to the impression cylinder.
A high-precision optical system
bundles the laser beam on the plate
Sharp dots directly onto the plateThe modern imaging system of the 74
Karat consists of two thermo-optical
imaging heads for constant, dot-sharp
image quality and a very high repetitive
accuracy in production. Each head possesses
40 laser diodes. Plates are imaged
with screen rulings up to 200 lpi
and at resolutions of 2400 or 2540 dpi,
whereby the minimum dot size is approx.
15 µm.
Process-free printing platesThe thermal PEARLdry printing plates
from Presstek, one of the leading suppliers
of direct imaging technologies,
are ablative plates. This means that the
developing process can be eliminated.
After imaging, the plates are cleaned
with a special dry cleaning system and
are then ready for printing. This shortens
job cycles and is friendly to the environment.
Register accuracy on all substrates
The exact imaging of the printing plates directly on the two plate cylinders, and full completion of four-colour printing without gripper transfers on the triple-size impression cylinder, are guarantees for exact register without time-consuming and waste-intensive corrections. The software of the 74 Karat also supports innovative algorithms which compensate for the material-dependent changes in the dimensions of the paper during four-colour printing.
The exact imaging of the printing plates directly on the two plate cylinders, and full completion of four-colour printing without gripper transfers on the triple-size impression cylinder, are guarantees for exact register without time-consuming and waste-intensive corrections. The software of the 74 Karat also supports innovative algorithms which compensate for the material-dependent changes in the dimensions of the paper during four-colour printing.
Constant results without ghosting
The plate and blanket cylinders of the 74 Karat are double-sized. The two plates on each plate cylinder are inked alternately with their appropriate colours, namely black/magenta in the bottom unit and cyan/yellow in the top unit. The sheet to be printed runs around the impression cylinder twice without any gripper transfers, whereby it receives the black and cyan separations on the first revolution, followed by magenta and yellow on the second. Before each contact with the relevant printing plate, each inking unit completes one rotation without contact. This ensures uniform plate inking and ghost-free print, regardless of the image.
The plate and blanket cylinders of the 74 Karat are double-sized. The two plates on each plate cylinder are inked alternately with their appropriate colours, namely black/magenta in the bottom unit and cyan/yellow in the top unit. The sheet to be printed runs around the impression cylinder twice without any gripper transfers, whereby it receives the black and cyan separations on the first revolution, followed by magenta and yellow on the second. Before each contact with the relevant printing plate, each inking unit completes one rotation without contact. This ensures uniform plate inking and ghost-free print, regardless of the image.
Keyless Gravuflow inking unit
The Gravuflow™ keyless inking unit
The revolutionary, temperature-controlled Gravuflow™ inking unit has no ink keys, and brings the press into colour extremely quickly. Makeready times and waste are reduced to a minimum. Even with high-volume jobs, or split runs printed simultaneously at different locations, constant printing quality is guaranteed.
The revolutionary, temperature-controlled Gravuflow™ inking unit has no ink keys, and brings the press into colour extremely quickly. Makeready times and waste are reduced to a minimum. Even with high-volume jobs, or split runs printed simultaneously at different locations, constant printing quality is guaranteed.
Gravuflow-Animation
With each rotation of the ceramic-coated
anilox (Gravuflow) roller, a thin coat
of ink is applied to the single-sized ink
forme roller. A doctor blade removes
the excess ink from the anilox roller.
This leads to fast, uniform printing results
without the operator constantly
having to intervene. He consequently
has more time for other tasks.
The 74 Karat is thus the ideal means of
production for high-quality printing in
short to medium runs, with a printing
quality which stands out clearly above
other DI presses on the market.
The 74 Karat combines high-quality
waterless offset printing with a fully
digital workflow and a high degree of
automation.
Exact job calculation
A complete job change with blanket washing, plate change, imaging in the press, cleaning and inking of the new plates lasts about 17 minutes, depending on the individual job data. The start-up waste until the first saleable sheet is approx. 10 sheets. This means that job throughput times can be planned very accurately.
A complete job change with blanket washing, plate change, imaging in the press, cleaning and inking of the new plates lasts about 17 minutes, depending on the individual job data. The start-up waste until the first saleable sheet is approx. 10 sheets. This means that job throughput times can be planned very accurately.
Cost per printed copy
Compared to other DI presses in this
format class, the individual operations
within the job change are remarkably
streamlined, which is reflected in shorter
job cycles.
The high production speed of 10,000
sheets per hour also makes it possible
to print jobs of 15,000 copies and
more with the same cost-effectiveness.
The waterless offset plates allow
runs of up to 100,000 impressions, as
may also occasionally be printed on the 74 Karat in larger printing companies.
With a substrate versatility covering
materials from 0.06 to 0.5 mm
in thickness, the press is also ideally
suited for printing cardboard. The accepted
sheet formats range from 210 x
297 mm (A4) up to 520 x 740 mm.
Turntable
The design of the 74 Karat makes its
unnecessary to turn piles manually before
printing the reverse side of the
sheet, as the press itself turns each
sheet on its way to the delivery. In
conjunction with the fully automatic
turntable (optional), it is possible to
proceed to the second pass for work-and-turn jobs with almost no delay. The
74 Karat is thus in many cases faster
and more cost-effective in production
than long unit-type perfecting presses,
especially for short runs.
Even faster with varnish
The optional dispersion coating unit for the 74 Karat extends the application profile of the press into the field of inline finishing. In addition, thanks to the drastic reduction in the drying time, the coating unit permits immediate printing of the reverse of the sheet, after renewed imaging of the printing plates.
The optional dispersion coating unit for the 74 Karat extends the application profile of the press into the field of inline finishing. In addition, thanks to the drastic reduction in the drying time, the coating unit permits immediate printing of the reverse of the sheet, after renewed imaging of the printing plates.
Dispersion coating unit
With appropriate imposition to permit
further use of the same forme, it is
even possible to print the reverse without
any waiting time whatsoever. An
important advantage of the 74 Karat
here is that the sheet is printed from below. This means that the pile only
has to be rotated by 180°, but does
not have to be turned. The 74 Karat is
thus practically unbeatable when it
comes to printing short-run four-page
A4 products with full colour on both
sides of the page.
As a rule, it is possible to cut or fold
the varnished sheet after only an hour.
The drastically reduced drying time is a
significantly positive factor in production
efficiency.
The result:
more jobs per shift or day and very short delivery times.
more jobs per shift or day and very short delivery times.
The oxidative-drying Toracard inks
were optimised specially for the 74 Karat
The 74 Karat with coating unit can be
equipped with a further accessory
package to handle plastic substrates.
This option permits printing on a broad
diversity of materials, such as
PVC (polyvinyl chloride),
ABS (acrylonitrile-butadiene styrene),
PC (polycarbonate),
PS (polystyrene) and
PET (polyethylene terephthalate).
This enables the cost-effective production
of credit cards, plastic cards, adhesive
labels, projector foils, packaging
films, metal-coated stocks, lenticular
materials (3D and changing-image effects)
and PVC advertising banners, to
name but a few examples, in the excellent
quality of waterless offset and
even in small numbers. The oxidative-drying
Toracard inks used were optimised
specially for the 74 Karat.
Minor modifications for major added
value
The ability to print on plastic substrates extends the scope of applications of the 74 Karat into a very profitable market segment. Unlike conventional sheetfed presses, the 74 Karat foregoes UV inks and varnishes and instead uses modified inks and dispersion varnishes formulated for waterless offset. The modifications to the press itself involve the ink supply system, the use of special blankets, new washing beams and washing solvents, and antistatic devices for the feeder and delivery. It is thus possible to achieve excellent results with a bare minimum of alterations to the standard press.
The ability to print on plastic substrates extends the scope of applications of the 74 Karat into a very profitable market segment. Unlike conventional sheetfed presses, the 74 Karat foregoes UV inks and varnishes and instead uses modified inks and dispersion varnishes formulated for waterless offset. The modifications to the press itself involve the ink supply system, the use of special blankets, new washing beams and washing solvents, and antistatic devices for the feeder and delivery. It is thus possible to achieve excellent results with a bare minimum of alterations to the standard press.
Quality and profit leads
Thanks to the very fast makeready and the perfect inking of the Gravuflow™ inking units, with just 10 sheets of start-up waste, the 74 Karat is practically predestined for demanding work on generally expensive plastic substrates. In comparisons with a conventional press, where it is often necessary to calculate 200 or 300 sheets of makeready waste, the profit potential for 74 Karat users in the printing of plastics becomes immediately clear.
Thanks to the very fast makeready and the perfect inking of the Gravuflow™ inking units, with just 10 sheets of start-up waste, the 74 Karat is practically predestined for demanding work on generally expensive plastic substrates. In comparisons with a conventional press, where it is often necessary to calculate 200 or 300 sheets of makeready waste, the profit potential for 74 Karat users in the printing of plastics becomes immediately clear.
From pre-press directly onto the plates in
the 74 Karat
With its interface to pre-press, the
74 Karat becomes a productive
output medium in a continuous digital
workflow. Through the operating console,
the printer has full access to the
printing jobs to be processed. While the
jobs are being prepared, they can be
copied onto the internal hard disk for
advance inspection. This serves as an
additional quality control.
Optimised workflows have been developed
to ensure a maximum degree of
proof matching.
The proven Creo Brisque workflow and
the Adobe® Extreme™ technology offer
the outstanding performance and flexibility
of a PDF workflow together with
the security and reliability of the CT/LW
production file format.
The highly efficient O.R.I.S. workflow
from CGS has been specially adapted for the 74 Karat. Configurable hot folders
take care of routine tasks and provide
for a high degree of automation in the
pre-press processes. Here, too, the latest
PDF technologies are used.
It is in fact a simple matter to integrate
the 74 Karat into a variety of
standard workflow environments, thanks
to the ability to process 1-bit TIFF
files.
Match-the-Proof
The jobs on the 74 Karat are imaged by the Expose engine within the press, remaining completely independent of RIP solution at the pre-press stage. The press and the RIP are merely linked to each other via the network. In terms of job processing responsibility, the 74 Karat distinguishes logically between file and proof preparation on the one hand, and file output or print production on the other. It is thus possible, with just a single data set, to perform plate imaging with any technically feasible screen ruling and resolution.
The jobs on the 74 Karat are imaged by the Expose engine within the press, remaining completely independent of RIP solution at the pre-press stage. The press and the RIP are merely linked to each other via the network. In terms of job processing responsibility, the 74 Karat distinguishes logically between file and proof preparation on the one hand, and file output or print production on the other. It is thus possible, with just a single data set, to perform plate imaging with any technically feasible screen ruling and resolution.
Highly colour-accurate digital proofs
can be printed out on various halftone
proofers or ink-jet devices, depending
on the workflow. The user is able to
choose from a whole range of accurate
and reliable proof systems and powerful
colour control options.
Precision colour management
Colour management is an integral part of the 74 Karat workflow. The printing press becomes the reference point for all colour management activities. All colour corrections are performed by the colour management module, which calibrates the press for a standard colour space or reference print environment, such as Euroscale Cromalin, SWOP or MatchPrint. Within the colour management workflow, the digital proofer is adjusted to match the press characteristics.
Colour management is an integral part of the 74 Karat workflow. The printing press becomes the reference point for all colour management activities. All colour corrections are performed by the colour management module, which calibrates the press for a standard colour space or reference print environment, such as Euroscale Cromalin, SWOP or MatchPrint. Within the colour management workflow, the digital proofer is adjusted to match the press characteristics.
As a result, the proofer effectively simulates
the 74 Karat, which in turn
means that the print matches the proof
exactly. The 74 Karat could equally be
calibrated to the existing company
standards of the individual user.
Its high proof-matching accuracy also
makes the 74 Karat an ideal tool for
printing jobs which can be received and
handled via the Internet. Even with
complicated and critical printing jobs,
the personal signature of the customer
on the first printed sheet can generally
be dispensed with.
Softproofs in conjunction with the relevant
Internet gateways and accurately
calibrated computer screens or remote
proofs using accurately calibrated printers
extend the possibilities of the
"distribute – then print" scenario with
the 74 Karat, including transfer and
quality control of the print data via the
Internet.
Such functions are currently the subject
of intensive development work
and testing by KBA in cooperation with
both users and leading software
suppliers.
With its outstanding strengths, colour
and register stability, high offset quality,
standardised printing process and
cost-effectiveness, alongside the possibilities
for developing new business
options, the 74 Karat is an interesting
value-for-money alternative to other DI
presses available on the market in this
format class.
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Formats and substrates
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| Minimum sheet format: | 210 x 297 mm | 8 1/4" x 11 3/4" |
| Maximum sheet format: | 520 x 740 mm | 20 1/2" x 29" |
| Maximum print format: | 508 x 735 mm | 20" x28 1/2" |
| Substrates: | 0.06 – 0.3 mm (up to 0.5 mm as an option) | 2 - 12pt (up to 20pt) |
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Maximum production output
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10,000 sheets/hr | |
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Plates
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Presstek PEARLdry aluminium plates 20 plates per book (for 10 jobs) | |
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Inks
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Modified inks for waterless offset in 2 kg (4lb 8oz) ink cartridges | |
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Press dimensions and weight (excluding console, air cabinet and chiller)
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| L x W x H: | 3.880 x 2.200 x 2.150 mm | 153" x 83" x 84" |
| Weight: | approx. 13 t | |
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Maximum pile height
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| Feeder: | 600 mm | 23 1/2" |
| Delivery: | 600 mm | 23 1/2" |
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Power supply
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65 kVA | |
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Imaging parameters
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| Resolution: | Imaging at 2,400 dpi or 2,540 dpi with screen ruling max. 200 lpi | |
| Diodes: | 40 per imaging head | |
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Recommended operating environment
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| Temperature | 18 – 26°C | 64.5° - 77°F |
| Relative humidity: | approx. 55% | |
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With inline coating via coating unit (optional)
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| Maximum production output | 8,000 sheets/hr (dependent on substrate) | |
| Substrates: | 0.10 – 0.50 mm | 4 - 20 pt |
| L x W x H: | 3.880 x 2.310 x 2.400 mm | 153" x 91" x 94" |
Subject to technical modifications
The following literature can be downloaded in PDF.
Alternativlely, we would be happy to send it to you in print. Please use our order form.
Alternativlely, we would be happy to send it to you in print. Please use our
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Case Studies 74 Karat
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74 Karat expands portfolio of Munich media service provider
Gloor Cross Media GmbH; Munich, Germany |
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74 Karat as Proof Printer
Vignold Group; Ratingen, Germany |
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Digital and Commercial Printers Expand Sales Mix with DI Technology
"Universal Press Inc." & "Crosstech Communications Inc"; Chicago, USA
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'Carefree Package' for Customers
printit! Digitaldruck; Essen, Germany |
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What level of quality can I expect from the 74 Karat press ? How do you define quality?
Quality on the 74 Karat is equal to that of any high-quality, 4-colour offset press. Quality parameters include the ability to lay down high density, smooth solids over the entire press sheet along with a crisp, uniform dot structure. The imaging system can produce screen rulings up to 80l/cm with no loss of quality in dot structure. The Gravuflow inking system eliminates the risk of ghosting.
Quality on the 74 Karat is equal to that of any high-quality, 4-colour offset press. Quality parameters include the ability to lay down high density, smooth solids over the entire press sheet along with a crisp, uniform dot structure. The imaging system can produce screen rulings up to 80l/cm with no loss of quality in dot structure. The Gravuflow inking system eliminates the risk of ghosting.
How has the 74 Karat press been optimised for waterless printing?
Waterless printing depends upon temperature control along the entire ink path. The 74 Karat press has independent temperature controls on the Gravuflow roller, form roller and plate cylinder for consistent, predictable and high-quality results.
Waterless printing depends upon temperature control along the entire ink path. The 74 Karat press has independent temperature controls on the Gravuflow roller, form roller and plate cylinder for consistent, predictable and high-quality results.
How do you control colour on the press without ink keys?
The press and the inking system are much more consistent and predictable than on a conventional offset press. Colour is established by the 74 Karat colour management system prior to imaging. This consistency also allows you to match a digital proof more reliably to the output of the 74 Karat press than to the output of a conventional press.
The press and the inking system are much more consistent and predictable than on a conventional offset press. Colour is established by the 74 Karat colour management system prior to imaging. This consistency also allows you to match a digital proof more reliably to the output of the 74 Karat press than to the output of a conventional press.
What is the Gravuflow inking system?
The major components of this inking system are the ink duct with doctor blade, Gravuflow roller and form roller. There are no ink keys, so ink application is standardised, reliable and eliminates operator error.
The major components of this inking system are the ink duct with doctor blade, Gravuflow roller and form roller. There are no ink keys, so ink application is standardised, reliable and eliminates operator error.
Ink duct: sensors monitor the volume of ink and maintain an optimum level, minimising ink surplus.
Gravuflow roller: located between the ink duct and the form roller. The fine cells and the two doctor blades assure that a uniform ink film is maintained on the Gravuflow roller and transferred to the form roller.
Form roller: the circumference of the form roller is identical to the length of the plate. This ensures uniform inking regardless of image or coverage during each revolution. This virtually eliminates any mechanical flaws such as ghosting.
What paper types and thicknesses can be printed on the 74 Karat press?
The press can print on practically all uncoated and coated stock from 0.05 mm (0.002 inch/2pt) to 0.3 mm (0.012 inch/12pt).
The press can print on practically all uncoated and coated stock from 0.05 mm (0.002 inch/2pt) to 0.3 mm (0.012 inch/12pt).
Which digital front ends and pre-press workflows are supported?
The 74 Karat press supporteds both Adobe PostScript bitmap and Scitex CT/LW workflows. Current users generally use a CreoScitex Brisque digital front-end as a pre-press station.
The 74 Karat press supporteds both Adobe PostScript bitmap and Scitex CT/LW workflows. Current users generally use a CreoScitex Brisque digital front-end as a pre-press station.
Which plates can be used on the press?
The 74 Karat press requires waterless, process-free aluminium plates which can be imaged at approximately 830 nm. At present, Presstek PEARLdry plates are the only ones available; they have a maximum service life of 100,000 impressions.
The 74 Karat press requires waterless, process-free aluminium plates which can be imaged at approximately 830 nm. At present, Presstek PEARLdry plates are the only ones available; they have a maximum service life of 100,000 impressions.