Demand of Dot proofing or Screen Proofing
One of the great controversies plaguing the printing industry
is the argument over halftone proofs and whether they are
truly needed. On the one hand, you have those who say they
don¡¯t need halftone proofs: ¡°Why should I? Since I am already
getting color approval, all I need is a proof that shows how
the color will print.¡± On the other hand, you have those who
swear by the halftone proof, claiming they need to be able
to predict moire. ¡°I don¡¯t want the client to see an image
that is smoother and more detailed than what I can achieve
on press,¡± they say.
Most inkjet proofers use error diffused or frequency-modulation
technology. The advantage of this is that it produces a smooth,
continuous-tone quality. The disadvantage is that this does
not replicate halftone screens. Color management systems (CMS)
complicate the issue. When remapping the inkjet color gamut,
CMS uses additional dots to match the printing press gamut.
This is especially true with six-color proofers. While six
colors provide a much wider spectrum for matching special
colors and different types of presses, it adds colors that
are not present in the CMYK rosette.
Luckily, inkjet technology has come a long way. With the
right screening technology, and a proofer that can print 1440
x 1440 dpi, dot-for-dot halftone reproduction becomes a reality.
It is even possible to achieve dot simulation at 720 dpi,
which is sufficient for predicting certain types of moire.
Although dot simulation is not an exact representation of
the halftone rosette, it more closely represents how the final
printed sheet will appear. It can also predict two types of
moire?color moire, which results from incorrect screen angles,
and subject moire, which is the result of a complex pattern
such as a checkered print interfering with the halftone screen.
Dot-for-dot halftone proofs print the details of the screening
structure exactly as it will appear on press. The rosette
patterns are identical, so all types of moire effect can be
accurately predicted. The individual dots on the proof have
the same shape, size and color. In addition to a resolution
of 1440 dpi to recreate an exact rosette, a proofer must be
able to handle multi-density inks and produce ink drops of
no more than five picolitres. Furthermore, the RIP must generate
the same screen rulings and angles, and interpolate the data
in exactly the same way as the platesetter RIP.
Why Dot proofing? Why Screen
For many years the prepress industry has been looking for
a digital proofing solutions to correct errors in pages before
final output to film or plate. Most of the digital proofing
solutions come with its own PostScript¢âRIP with color management
system for small or large format printers. These solutions
require the composite PostScript¢â pages to be sent, first
to the proofer RIP to produce the digital proof. After a confirmation
proof is produced these pages have to be re-sent as a separated
PostScript¢â files to a totally different RIP that sends the
Hi-Resolution data to a imagesetter or platesetter. This RIPping
twice with two different RIPs, generating two totally different
Both the ¡®Digital Proof¡¯and the ¡®Final Print¡¯ will definitely
not match. Text reflows, font errors,
OPI faults, trapping and other PostScript¢â odd problems are
common. This dilemma of two different RIPs is simply overcomed
by VisualDot, which uses Hi-Resolution data to the Final Print
itself for Dot-proofing. It helps you secure absolute Data
integrity of your Halftone Screening in CTP/CTF Delivering
screened inkjet proofs with Contract Quality & Assured
Beyond the Continuous Color
You can save your Cost and Time by early recognition of Moires
and Trapping errors with Dot-for-Dot reproduction. VisualDot
is an essential solution in Dot-proofing for the prepress
VISUAL DOT digital screen proofing software is a revolution
in Dot-Proofing for the Pre-Press Industry.
Color-accurate continuous proofs are not always sufficient
when a real contract proof is required.
In many cases, a proof is needed that not only reproduces
color accuracy, but also shows the halftone dot pattern. VisualDot
provides the ability to resample high-resolution, pre-separated,
screened bitmap plates from the CTP/CTF RIP into a accurate
inkjet-printed representation with screen angle, screen ruling
and dot shape preserved in their entirety. Halftone proofs
are vitally important for identifying problems like Moire
artifacts, incorrect trapping settings or interpretation errors
in the imagesetter or CTP RIP before plates are exposed or
the print process begins.
Halftone proofs help users minimize the cost and time losses
resulting from prepress errors.
Continuous Color Proof is
NOT enough for continuous proofing purpose itself
Screened DOT proof delivers Contract Quality of proof in color
and details as well as screen dots. The prepress industry
has long time history and software technology, mechanical/chemical
printing technology and optical device technology has been
tremendously enhanced so far. However, it is physically difficult
to produce exact 'press-look' proof with inkjet printers because
of different ink system, microscopic details, characteristics
of media and etc. But in most of prepress industry, professionals
have developed their own rigid way of continuous color proofing
with experienced trials and errors, which cannot be caught
up with by any intelligent software technology. However, even
professionals have difficulties in producing toned-down color,
high-resolution of small fonts and narrow lines of the press
in inkjet color proofing. That's the limitation of color proofing
without screen dots. VisualDot will deliver the most press-look
proof by overcoming the limitation of continuous color proofing.
People will get the press-look colors and details in small
fonts and narrow lines by simply adding VisualDot to the same
continuous color proofing workflow.