By
Calvin Siew
27/01/2005
URL:
http://asia.cnet.com/reviews/printers/0,39051182,39163795,00.htm
In the world of photo printing, the market is invariably moving toward more
affordable and better quality outputs. It may come as a surprise, but in a
system that's often judged based on the performance of the hardware, the most
important part of the whole printing system is really the inks. These little
drops of liquid can affect everything from print speeds to something as insignificant
as paper curls.

Photo courtesy of
HP |
|
For the desktop world, the affordable, quality photo printing space is really
carved up into two groups. The dye-based ink advocates and the pigment-based
proponents, namely Epson. Depending on whom you talk to, each will claim superiority
over the other. So which one is the right one for you?
Common arguments
In general, dyes bind to
paper better than pigments and offer superior color reproduction and glossiness,
yet they suffer from low fade resistance to light and air (ozone). In addition,
colors tend to bleed together when exposed to water.
In the case of pigmented
inks, the pigments remain in a solid state when mixed with most liquids. These
are dispersed throughout the ink with the use of special additives, preventing
the particles from clumping together and sinking to the bottom of the liquid.
Still, there's a need for the cartridges to be shaken like household paint to
prevent the pigments from clumping together and settling at the bottom (ever
squinted at the instructions for Epson's DURABrite ink installations?). Also,
because the pigment particles are too large to penetrate the paper coatings,
you'll find bumps on the surface of the media.
| 
Pigment
particles adhering to the paper coating, giving surface bumps.
Picture courtesy
of HP |
|

Picture courtesy
of Epson |
|
Is
that it?
If these were the case, it
might appear that if you want long-lasting prints, you'd go for pigments, while
if you're finicky about image quality, dyes might be the way to go. Unfortunately,
while the arguments above are correct, it doesn't and shouldn't apply to printers
we purchase today. Manufacturers have gotten around each of the problems with
various technologies.
For instance, fade resistance
is not just about colorants. Paper media is another medium to aid in prevention
and we'll be talking about this in the second article of our series on photo
printing. On their part, manufacturers have made dye colorants with more sophisticated
dye structures to increase resistance and added specialty components--often
proprietary--to prevent problems like color bleeds.
For the problem with pigments,
Epson's core firing technology takes care of the issue of clumping particles.
At the heart of each Epson printer is its piezo-electric elements. These delicate
crystals vibrate each time voltage passes through. With a piezo element at each
nozzle vibrating tens of thousands of times per second, there is no physical
need for you to take the cartridge out to shake it, potentially dealing with
messy ink leaks. In terms of uneven surfaces, the Japanese company has introduced
an eighth "ink" which is a gloss optimizer to fill in the white spaces
on the surface of the paper.

Picture courtesy
of Epson |
|
So what should I pick?
The print industry is very much like any other business. It
has everything to do with tradeoffs. When it comes to photo printing, one question
to be asked before you make your decision is: How much are you willing to give,
in terms of fade resistance, for photo print speeds? Below, you'll find a table
which summarises our findings from printer reviews of the top three inkjet manufacturers.
The manufacturers were ranked against each other, with "1" depicting
first place and "10" being the lowest score. The figures for fade resistance are the best known values from WIR's (Wilhelm Imaging Research) Display Permanence Rating (glass-filtered) tests.
| |
Fade
resistance |
Image
quality |
Speed |
| Canon (Dye) |
7 (38 years) |
1 |
1 |
| Canon (Dye-sublimation) |
10 (7 years) |
6 |
6 |
| Epson
(Dye) |
8 (27 years) |
5 |
8 |
| Epson (Pigment-based) UltraChrome |
1 (150 years) |
3 |
7 |
| Epson
(Pigment-based) DURABrite |
5 (80 years) |
9 |
9 |
| HP
(HP57 tricolor) |
9 (15 years) |
8 |
3 |
| HP (HP57+HP58 photo cartridge) |
6 (73 years) |
4 |
5 |
| HP (HP95 or HP97 tricolor cartridge in 3-color print mode) |
4 (82 years) |
7 |
2 |
| HP (HP95 or HP97 + HP99 photo cartridge in 6- or 8-ink print mode) |
3 (108 years) |
2 |
4 |
| HP
(HP100 gray photo cartridge) |
2 (115 years) |
- (B&W only) |
- (B&W only) |
From here, it's apparent
where the focus lies for each company. You'll find that for the desktop space,
fade resistance is of priority to Epson and HP, while speed is with Canon. Although
image quality is subjective, we think Canon's latest Pixmas have that under belt.
There remain a few things
to be mentioned with regard to the results. Although Epson's pigment-based inks suggests stronger fade-resisting performance, this was accomplished on the manufacturer's heavyweight Matte paper--which isn't particularly everyone's cup of tea. With glossy photo media, WIR rates the Epson UltraChrome inks for 104 years and the rankings skew toward HP's favor. There really isn't much to differentiate between pigments and dyes on the upper end of the market when we talk about fade resistance.
Similarly, while we ranked
the DURABrite prints last in our image quality comparisons, the outputs were still pleasing. We found that with our Epson Stylus C65, outputs turned out great with little dithering and no banding visible when set to the best-quality mode. As such, we think most users won't have much to complain about those water-resistant prints.
From the results, you will
notice a couple of things. When it comes to printers with more than four inks,
you'll see that HP pretty much has a grip on everything, giving out the most
balanced performance over the three ratings. However, for users looking for
four-ink units, Canon and Epson printers present a much better deal, with Canon
producing fast prints and Epson optimized for fade-resisting outputs.