2. Let’s Watch How It Works …
• http://www.youtube.com/watch?v=0gEEaFT5
z84&list=PL9EC96E5ADAC7FCF1
• http://www.youtube.com/watch?v=XUlBueqS
tg4
3. 9 types of printing
Offset lithography
Engraving - think
fine stationery
Thermography -
raised printing, used
in stationery
Reprographics -
copying and
duplicating
Digital printing -
limited now, but the
technology is
exploding
Letterpress - the
original guttenberg
process (hardly
done anymore)
Screen - used for t-
shirts and billboards
Flexography -
usually used on
packaging, such as
can labels
Gravure - used for
huge runs of
magazines and
direct-mail catalogs
4. Offset printing.
• Also known as offset
lithography.
• Its relatively
inexpensive and prints
very well.
• What is the off-set
printer based on?
• That water and oil repel
each other.
http://www.youtube.com/watch?v=ss5soAuolks&list=PL9EC96E5ADAC7FCF1
5. Offset Printing
• Plates are used to hold
the ink and water
prevents the ink from
running onto the spaces
where ink should not be.
• It is transferred to a
rubber blanket.
• The image is then off-set
from the blanket to the
paper.
• Why do they use a rubber
blanket instead of just
printing to the paper.
6. Flexography
1.Used to print on flexible
material such as plastic
bags, which would be
torn apart in an off set
printer.
2.Uses soft plate and
prints plate to surface.
3.The ink is relatively thin
and dries quickly on
non-porous materials
such as plastic and foil.
7. Letterpress
1.Originated in Asia using
individual letters made of
clay.
2.Gutenberg developed the
process in Germany using
characters molded from
lead. (Where the leading
came from)
3.Characters on the plate are
higher than the material
surrounding them.
4.Rubber stamps work on the
same principle.
8. Engraving
1.Images are cut into the metal plate
rather than raised above the plate like
letterpress.
2.The surface of the plate is covered
with ink, then wiped clean, leaving
the engravings full of ink.
3.The press then forces paper into the
inked recesses, transferring the image
to the surface of the paper.
4.Engraved paper feels slightly indented
behind its image areas.
9. Thermography or raised printing
1.Can be produced more quickly
then engraving and to the
untrained eye looks and feels
similar.
2.Thermography is a four-stage
process that begins with offset
printing using inks that dry slowly.
3.Next the sheets are sprayed with a
fine resin powder which sticks to
the wet ink
4.Then a vacuum unit collects the
powder that didn’t stick to the ink
5.Finally a heating unit melts the
remaining powder into the ink.
The powder swells as it melts, so
the printing rises above the
surface of the paper
10. Laser printer
• Cleaning-The drum is cleaned of
any residual toner and electrical
charge.
• Conditioning-The drum (which is
as wide as a sheet of paper) is
conditioned to contain a high
electrical charge.
• Writing-A laser beam discharges
a lower charge to only those
places where toner is to go.
• Developing-Toner is placed on
the drum where the charge has
been reduced.
• Transferring-A strong electrical
charge draws the toner off the
drum onto the paper.
• Fusing- Heat and pressure fuse
the toner to the paper.
