13: Printing Technology

Digital Image Formation
Printing Technology
Printing Technology
Timeline
!
1439: Printing Press!
1796: Lithography!
1903: Offset Printing Press!
1907: Screen Printing!
1957: Dye-Sublimation!
1960 s: Photocopier!
1969: Laser Printer!
1970: Dot Matrix Printer!
1976: Inkjet Printer!
Printing Technology
Printing
Devices
• Dye Sublimation
• Inkjet
• Laser
• Chemical (Silver Processes)
Printing Technology
Dye Sublimation
Printers
(or dye-sub printer) !
• Employs a printing process that uses heat to
transfer dye to a medium such as: !
• plastics, glass, ceramics, printer paper,
photographic paper, or fabric.!
Printing Technology
Dye Sublimation
Printers
• Continuous Tone printing device
• Heat Transfer Process
• Creates 24 bit color per pixel by heating & vaporizing
the cyan, magenta, yellow, and black dyes in different
intensities by varying the heat in 256 levels.
• Uses CMY colors
• Cyan, Magenta, Yellow
Printing Technology
Dye Sublimation
Printers
• Material
• The printing dye is stored/contained on
cellophane ribbon and is made up of three color
panels.
Printing Technology
Dye Sublimation
Printers
Dye Sublimation Printers
• Advantages
• A superior color gamut to inkjet printing
• Prints are dry and ready to handle as soon as they exit
the printer
• Cost - media packs containing both ribbon and paper
yields a fixed cost per print
• The whole printing cycle is extremely clean
• no liquid ink / no print heads to get clogged
• fewer moving parts that can break down
• Laminate coating to protect print from water
• UV coating protects print from UV light damage
Dye Sublimation Printers
• Dis-advantages
• Printing Size - only one size pre-printer
• Waste - up to 95% of the dye may be wasted for a typical print
• Security Risk - a perfect color-separated negative image of the
printed page is created on the supply roll color panels
• Last but not least, Dye Sublimation Printers are not good for
producing continuous tone Black and White prints.
Printing Technology
Dye Sublimation
Printers
!
Canon $89.95 6 Printer
Fuji $2495 8 Printer
Printing Technology
Ink Jet Printers
•  Propels variably-sized droplets of ink onto the paper
surface.!
• Microscopic droplets of cyan, magenta, yellow, and
black imitate the color of the pixel.!
• One pixel consists of many small droplets of varying
size and color, therefore there is no straightforward
relationship between the dots and the pixels of the
image!
!
Printing Technology
Ink Jet Printers
!
!
Printing Technology
Ink Jet Printers
There are three main technologies in use in
contemporary inkjet printers:!
• Thermal
• Piezoelectric
• Continuous!
Printing Technology
Ink Jet Printers
!
Thermal!
Canon, HP, Lexmark
!
• Uses print cartridges with a series of tiny electrically
heated chambers that causes a steam explosion in
the chamber to form a bubble, which propels a droplet
of ink onto the paper.!
• The ink used is water-based inks using pigments or
dyes.!
Printing Technology
Ink Jet Printers
!
Piezoelectric!
Epson (MicroPiezo)
!
• Uses a piezoelectric material in the ink-filled chamber
behind each nozzle instead of a heating element.!
When voltage is applied, the piezoelectric material
changes shape or size, which generates a pressure
pulse forcing a droplet of ink from the nozzle!
Printing Technology
Ink Jet Printers
!
Piezoelectric!
Epson (MicroPiezo)
!
Printing Technology
Ink Jet Printers
!
Piezoelectric!
Epson (MicroPiezo)
!
• Piezo technology allows a wider variety of inks than
thermal or continuous ink jet.!
• Print heads are built with robust construction and are
designed for high volume production, faster print
speeds, and lower costs.!
• The print heads apply between zero to eight droplets
of ink per dot and only where needed!
Printing Technology
Ink Jet Printers
!
Continuous
!
• Continuous ink jet printers are used commercially for
printing of products and packages.!
Printing Technology
Photographic Ink Jet Printers!
Ink Set!
Printing Technology
Photographic Ink Jet Printers!
Ink Types!
!
• Dye-Base Ink!
• Pigment-Base Ink!
Printing Technology
Photographic Ink Jet Printers!
Dye-Based Ink!
• Advantages!
• Much stronger than pigment-based ink!
• Can produce more color for a given density!
• Dye on the paper is not affected by water or other solvents!
• Keeps reflections even resulting in less Gloss Differential and
Metamerism!
Printing Technology
Photographic Ink
Jet Printers!
Dye-Based Ink!
Disadvantages!
!
• Have a tendency to absorb into paper leading to
bleeding or dot gain . !
• Poor Lightfastness resulting in fading prints.!
Printing Technology
Photographic Ink Jet Printers!
Pigment-Based Ink!
Advantages!
• No Dot Gain, the ink rest on the surface of the paper!
• Less ink is needed to create the same intensity of color !
as with dye-based inks!
• Pigmented inks offer improved Lightfastness.!
Printing Technology
Photographic Ink Jet Printers
!
Pigment-Based Ink!
• Disadvantages!
• Clogging of print heads!
• Gloss differential!
• Metamerism - ( when two matching color samples do not
match when viewed under different light sources or from
different angles)!
Printing Technology
Photographic Ink Jet Printers!
Inks and Dot Gain!
Printing Technology
Photographic Ink Jet Printers!
!
• Lightfastness!
• Is the lifetime of the print without any fading!
• Some paper-ink combinations claim to last 70-200 years.!
Printing Technology
Photographic Ink Jet Printers!
!
• Waterfastness!
• Water-resistance!
• Dye-based ink is only water-resistant on specific glossy
photo papers!
• Pigment-based ink is water-resistant on any paper surface!
Printing Technology
Photographic Ink
Jet Printers!
!
• Gloss Differential!
• Pigment-based printers: no ink is applied to white areas
therefore this results in microscopic valleys that can cause
non-uniform reflections when viewed from different angles.
Also, it can be a problem within different colors. !
!
!
Printing Technology
Photographic Ink
Jet Printers!
!
• Metemerism!
• Pigment-based Printers: undesirable colorcast caused by
mixing different colors to reproduce shades of gray in a B&W
print.!
!
!
Printing Technology
Photographic Ink
Jet Printers!
!
• Image PPI vs. Printer DPI!
• Because the printer places many dots (droplets) to
represent one pixel the printer s DPI refers to the
amounts of droplets that is printed on the paper and is
not directly related to the images PPI/DPI managed in
image processing.!
Printing Technology
Photographic Ink
Jet Printers!
!
Iris Printer 1987!
!
An Iris printer is a large format color inkjet printer
manufactured by the Graphic Communications Group of
Eastman Kodak
The prints are noted for their accurate color reproduction.!
!
Iris printers have also been used in the production of fine
art prints since the early 1990s. An early developer of the
technology in the fine art field was Graham Nash.!
!
Printing Technology
Photographic Ink
Jet Printers!
!
Iris Printer
• Iris printers use a continuous flow ink system to
produce continuous-tone output on various media!
• Unlike most ink jet printers which fire drops only when
needed, the Iris printers' four 1 micron glass jets flow
continuously under high pressure.!
• Drops that are not needed to form the image are deflected
electrostatically into a waste system. !
!
Printing Technology
Photographic Ink
Jet Printers!
!
GiclÈe
pronounced "zhee-clay"
!
is an invented name for the process of making fine art
prints from a digital source using archival ink sets and high
quality printing paper in a ink-jet printer.!
!
Printing Technology
Color Laser
Printers
!
are a common type of computer printer that rapidly
produces high quality text and graphics on plain paper!
!
Laser printers employ a xerographic printing process
but differ from analog photocopiers in that the image is
produced by the direct scanning of a laser beam
across the printer's photo-receptor.!
!
!
Printing Technology
Color Laser
Printers
Advantages!
!
• CMYK!
• Resolution up to 2400 dpi!
• Speed up to 100 color pages per minute!
• Cost cheaper per volume than any other printer!
!
Printing Technology
Color Laser
Printers
Disadvantages!
!
• Anti-counterfeiting ("secret") marks!
• Many modern color laser printers mark printouts
by a nearly invisible dot raster, for the purpose of
identification!
• Shock hazards!
• it is possible for a high voltage or a residual
voltage to be present on the various rollers, wires,
and metal contacts inside a laser printer!
!
Printing Technology
Color Laser
Printers
Disadvantages!
!
• Toner clean-up!
• Ozone hazards!
• the high voltages inside the printer can produce
ozone and nitrogen oxides!
!
• Respiratory health risks!
• some printers emit sub-micro particles which
some suspect may be associated with respiratory
diseases!
Printing Technology
Color Laser
Printers
Disadvantages!
• Media!
• Unable to print on coated photographic quality
paper!
!
!