Letterpress
Lithography
Letterpress is one of
the oldest methods of
printing and uses a
process called relief
printing. This means
that the area to be
printed stands above
the area not to be
printed. The image
area is inked and
transferred to paper.
Lithography relies on the principal that water
Letterpress Books with large
and grease do not mix. The printing plate is a
amounts of text,
totally flat sheet of aluminium produced
letterheads and
photographically and chemically treated. Ink is
business cards.
attracted to the chemically treated print area;
Lithography Newspapers,
the non-print area is later dampened with water
magazines, books,
to lift the ink off.
posters, letterheads
Method
Applications
Advantages
Disadvantages
Cost
Print run
Good quality in
terms of
sharpness and
solidity.
Few suppliers
Not economical for
colour work
Slow process
Only competitive 500 to 5000
for short runs and
reprints of
monochrome
A widely used
process
Many suppliers
Plate life limited to
150000 copies but can
be quickly remade
Most economical
process for
general printing
250 000 to 1
million
Expensive to set up
Very high print
runs required to
recover set up
costs
500 000 to
several million
Low cost
Several copies to
a few hundered
and packaging
Suitable for large amounts of plain text in one or
two colours using standard type faces,
Letterpress printing is mainly restricted to small
printers who economically printed items such as
letterheads and business cards. It is not suitable
for full colour pictures or pictures with fine detail.
Rotary letterpress is a
modern method of
continuous printing using
a relief plate wrapped
around a drum. The
image is transferred onto
a thin plastic sheet
photographically and the
unwanted area removed
by solvent.
Offset litho printing uses
a rubber roller to avoid
direct contact between
the paper and the
plate thus lengthening
the life of the plate and
preventing the paper
from becoming damp
through contact with
the water during
printing.
Lithography is ideal for single or multiple colour
work such as magazines, posters, letterheads,
packaging (inc. CD booklets) and tickets. For a
single colour letter head the minimum batch
quantity will be about 100 but approximately
250000 for a four colour process.
Flexography
Screen printing
Screen printing works
by passing ink through
the holes in a stencil
corresponding to the
area to be printed in
each colour.
The stencil can be made of paper or thin card
and are supported on a thin mash. The ink is
than spread and scraped forcing it through the
mesh and stencil on to the surface being
printed. Simple designs work best building
colours up layer by layer.
Similar to letterpress,
flexography uses a
flexible printing plate
made of plastic or
rubber. Used for many
types of packaging
particularly when the
medium is not
conventional paper.
It is particularly useful for printing materials such
as polythene food wrappers as they are very
thin and non porous. The inks are solvent based
and evaporate on contact making flexography
a high speed process suitable for very large
print runs of items such as carrier bags frozen
food packaging corrugated point of sale
materials and some wallpapers.
Colour printing
Modern colour printing uses a dot structure made up of the three primary colours and black to
create a full range of colours when superimposed onto each other. Each colour is printed one after
the other in a sequential process onto the same dot matrix structure. The dots are very small but can
be seen when viewed closely. The process of positioning one printing exactly over another is known
as registration.
Gravure
Expensive
Produced very
magazines, books
high quality print
and postage stamps work
Screen
Posters, t-shirts,
shop display
Printing
Can be printed on Only suitable for short
smooth absorbent runs
or rough surfaces. No fine detail possible
designing the blade to
squash the card rather
than cut in the required
Straight edges can be cut area.
using a guillotine, however
irregular shapes may be
Varnishing
cut in quantity using die
Varnishing can be added
cutters. This includes the
as the final stage of the
outside shape and any
printing process providing
internal holes.
a glossy protective finish.
A large shaped blade has
There are four types of
to be produced which
varnish; oil based, water
works in a similar manor to
based, UV and spirit based.
a pastry cutter stamping
out the required design.
Folds in the design can be Laminating
added at this stage by
The laminating process
Die cutting and
folding
Effect
Applications
bonds a thin layer of plastic
to the entire printed
surface. Similar in effect to
varnishing it provides a
more protective and glossy
finish although more that
twice as expensive.
Particularly useful if many
people are expected to
handle the product it is
often used for menus and
cartons.
Embossing
surrounding area. This is
done for both visual and
tactile effect, providing
a subtle look and feel of
quality. Embossing
involves a separate
stage in the production
process after varnishing
or laminating. Costs are
similar to printing and
therefore any product
requiring both printing
and embossing will
double the cost.
Embossing is the process
by which a portion of the
surface is raised above the
Advantages
Disadvantages
Die Cutting Packaging
Once set up, cutting dieSlow process
Unusual shaped papers can be reused many
times
Cost
Expensive for short
runs if special shapes
are required
Spirit
Protects paper and
Varnishing card
Looks more attractive
Cannot be added until
Easy process for
enhancing or protectingprinting ink is dry
product from scuffing
Low cost
Can be applied on the
printing press
UV
Heat cured coating
Varnishing which uses UV light
Enhances magazine
and book covers
Increases durability
Provides high-gloss
finish
Does not add any strength Half the cost of
to the product
laminating
Can be applied the
same time as printing
Laminating Cartons, special
brochures and
company reports,
menus
Increases durability
Provides high-gloss
finish
Expensive
Can peel and blister
Twice the cost of
varnishing
Laminating Special effects for
packing, business
cards etc.
Attractive, enhances
graphic designs
Expensive process
requiring special tooling
Doubles initial print
cost.