Re: Print Quality

From: Editor P.O.V. Image Service ^lt;[email protected]>
Date: 04/18/04-03:50:01 AM Z
Message-id: <>

Quality increase depends on several factors:

1) The dither pattern

2) The droplets

a) minimum picoliter size

b) size variability

3) dpi

4) # of ink colors

5) media printed upon

Assuming that #s 1, 4, 5 are constant, let's focus on 2 & 3

I'll assume you are looking at a printer that uses at least 6 colors as

Higher dpi can give you visibly better images until about 2880 x 2880
when working with droplet sizes below or equal to approximately 3
picoliters (assuming a variable droplet size printing engine). After
about 2880 dpi IMHO higher dpi is almost entirely hype.

What you want to look at, should your intentions be predominantly color
imagery, if the printer uses 3 picoliter or less droplets, are things
like the number of colors and the dither. The newer 1.5 and 1 picoliter
printers using 8 ink colors can give one smoother skintones and a
broader color gamut. BUT, the images don't look any less "dotty" than
say ones at 2880x2800 and 3 picoliters. At 1.5 or less picoliters, the
manufacturers can do away with the light cyan and light magenta inks,
replacing them with red and blue or red and green, etc., as the cyan and
magenta droplets can be made small enough to obviate the need for the
light cyan and light magenta.

Media is extremely important. Dot gain and media texture throw all the
issues of droplet size and dpi to the wind. (Dot gain is the increase
in size of the droplet when it soaks into a particular media.) That's
why glossy RC type (be they microporous or swellable polymer) materials
will generally show the best results (less dot gain) with higher dpi and
smaller droplets, when compared to matte cast coated or uncoated materials.

As a simple example, we can look at EPSON's older 1270 and 1280
printers. They have a 3 picoliter minimum droplet size, variable
droplet size, and a maximum 2880 x 2880 dpi. When doing B&W prints with
these printers and MIS's newest B&W hexset inks, there IS a visible
difference on glossy or lustre material at 2880 x 2880 over 1440 x 1440.
However, higher DPI on printers using similar droplet sizes shows no
perceived increase in print quality. But, if you print on matte
media, the difference between 2880 and 1440 essentially disappears.

This all very similar to buying a flatbed scanner in one sense. If you
intend to use a flatbed ONLY for print scanning, over 600 dpi, you find
virtually no increase in scan quality. The rest is hype.

Here's what I recommend to students at my "Putting Inkjet to Paper"
seminars: If you are SERIOUS about your printing and can't decide
between printers on other factors, create a representative sample print
from your own library of images - one that is representative of YOUR
work and of one you might be printing images similar to. Add a greyscale
21 step wedge to that image. Size the whole thing to 8 x 10. Put it on a
CD. Take it to a store and print it yourself or send copies to the OEM's
marketing people and have them send you sample prints made from that
image (untweaked by them) via their printers. Examine the quality of
each image against the others. (attendees at my seminars get sample B&W
and color prints done this way)

Just remember that this isn't going to address things like media and ink
archival qualities, reliability, ink costs, etc..

Hope this helps.. If you want an opinion, just let me know what printers
you are choosing between.

Keith Krebs

"Just some guy," caretaker of the Multiverse's largest EPSON printer
User Community (highly recommended by Vogon Poets and MegaDodo
Publications), at:
and the Multiverse's largest Canon printer User Community at:
"For the rest of you out there, the secret is to bang the rocks together

Received on Sun Apr 18 03:51:29 2004

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