194 PART 4 HOW DIGITAL PRINT-MAKING WORKS
How a Printer Rains Ink
to Create a Picture
Once considered little more than a toy for home PC users who wanted to play with graphics programs, the
inkjet printer has come into its own as a serious tool for serious photographers. Where once photos
from an inkjet were crude and quick to smear and fade, improvements have made some inkjet
photos indistinguishable to the naked eye from a traditional print—and without the smears
and fading.Inkjet printers use one or more
cartridges filled with different colors of
ink in different reservoirs. The cartridges
are locked into a print head. (Some
printers combine cartridges and the
print head as one unit.) The print head
travels back and forth on a sturdy metal
rod and spits colored inks onto a sheet
of photo paper that the printer has
grabbed from a stack and pushes
beneath the print head.1
Some printers strive to create larger gamuts—
the total range of colors they can produce—by
including additional color inks, such as green
and lighter shades of blue and red. A few print-
ers accept cartridges that contain nothing but
black and shades of gray for photographers
who specialize in black-and-white photography.2
Inkjet printers produce dots of color so
small we don’t even call them drops of
ink. They’re droplets. Droplets are
measured in picoliters—
1/1,000,000,000,000 of a liter.
That’s smaller than the human eye can
see. Droplets, such as those shown in
this hugely magnified scan, range from
1 to 10 picoliters.3