a powerpoint on the print industry

3. • Etching is the process of using strong acid or mordant to cut into the
unprotected parts of a metal surface to create a design in intaglio in the
metal (the original process—in modern manufacturing other
chemicals may be used on other types of material). As an intaglio
method of printmaking, it is, along with engraving, the most important
technique for old master prints, and remains in wide use today. In pure
etching, a metal (usually copper, zinc or steel) plate is covered with a
waxy ground which is resistant to acid. The artist then scratches off the
ground with a pointed etching needle where he or she wants a line to
appear in the finished piece, so exposing the bare metal.

4. • Linocut is a printmaking technique, a variant of woodcut in
which a sheet of linoleum (sometimes mounted on a wooden
block) is used for the relief surface. A design is cut into the
linoleum surface with a sharp knife, V-shaped chisel or gouge,
with the raised (uncarved) areas representing a reversal (mirror
image) of the parts to show printed. The linoleum sheet is inked
with a roller (called a brayer), and then impressed onto paper or
fabric. The actual printing can be done by hand or with a press.

5. • Screen printing is a printing technique that uses a woven mesh to support an ink-blocking
stencil to receive a desired image. The attached stencil forms open areas of mesh that transfer
ink or other printable materials which can be pressed through the mesh as a sharp-edged
image onto a substrate. A fill blade or squeegee is moved across the screen stencil, forcing or
pumping ink through the mesh openings to wet the substrate during the squeegee stroke.
Basically, it is the process of using a mesh-based stencil to apply ink onto a substrate, whether
it be t-shirts, posters, stickers, vinyl, wood, or other material.
• Screen printing is also a stencil method of print making in which a design is imposed on a
screen of polyester or other fine mesh, with blank areas coated with an impermeable
substance. Ink is forced into the mesh openings by the fill blade or squeegee and onto the
printing surface during the squeegee stroke. as the screen rebounds away from the substrate
the ink remains on the substrate. It is also known as silkscreen, serigraphy, and serigraph
printing. One colour is printed at a time, so several screens can be used to produce a multi-coloured
image or design.

6. • Woodcut—occasionally known as xylography—is a relief printing artistic
technique in printmaking in which an image is carved into the surface of a
block of wood, with the printing parts remaining level with the surface
while the non-printing parts are removed, typically with gouges. The areas
to show 'white' are cut away with a knife or chisel, leaving the characters or
image to show in 'black' at the original surface level. The block is cut along
the grain of the wood (unlike wood engraving where the block is cut in the
end-grain). The surface is covered with ink by rolling over the surface with
an ink-covered roller (brayer), leaving ink upon the flat surface but not in
the non-printing areas.
• Multiple colours can be printed by keying the paper to a frame around the
woodblocks (where a different block is used for each colour). The art of
carving the woodcut can be called "xylography", but this is rarely used in
English for images alone, although that and "xylographic" are used in
connection with block books, which are small books containing text and
images in the same block. Single-leaf woodcut is a term for a woodcut
presented as a single image or print, as opposed to a book illustration.

7. • Lithography (from Greek λίθος, lithos, "stone" and γράφειν, graphein, "to write") is
a method of printing originally based on the principle that oil and water do not mix.
Printing is from a stone (lithographic limestone) or a metal plate with a smooth
surface. It was invented in 1796 by German author and actor Alois Senefelder as a
cheap method of publishing theatrical works. Lithography can be used to print text
or artwork onto paper or other suitable material. Lithography uses simple chemical
processes to create an image. For instance, the positive part of an image is a water-repelling
("hydrophobic") substance, while the negative image would be water-retaining
("hydrophilic"). Thus, when the plate is introduced to a compatible
printing ink and water mixture, the ink will adhere to the positive image and the
water will clean the negative image. This allows a flat print plate to be used,
enabling much longer and more detailed print runs than the older physical
methods of printing (e.g., intaglio printing, letterpress printing).

9. • Letterpress printing is a technique of relief printing using a printing
press. A worker composes and locks movable type into the bed of a
press, inks it, and presses paper against it to transfer the ink from the
type which creates an impression on the paper. In practice, letterpress
also includes other forms of relief printing with printing presses, such
as wood engravings, photo-etched zinc "cuts" (plates), and linoleum
blocks, which can be used alongside metal type in a single operation, as
well as stereotypes and electrotypes of type and blocks. With certain
letterpress units it is also possible to join movable type with slugs cast
using hot metal typesetting.

10. • Rotogravure (Roto or Gravure for short) is a type of
intaglio printing process, which involves engraving the
image onto an image carrier. In gravure printing, the image
is engraved onto a cylinder because, like offset printing and
flexography, it uses a rotary printing press. Once a staple of
newspaper photo features, the rotogravure process is still
used for commercial printing of magazines, postcards, and
corrugated (cardboard) product packaging.

11. • The fourth traditional type of printing, screen process, includes silk
screen and has special applications in the printing industry. Silk screen
printing is a form of stencil printing, i.e., printing where the ink is
applied to the back of the image carrier and pushed through porous or
open areas. The image is on a piece of silk stretched on a frame and
backed by a rubber squeegee containing ink. The nonprinting areas on
the silk screen are blocked out, and the ink is pushed through the
porous areas corresponding to the design; the process is widely used for
posters and for printing on glass, plastics, and textured surfaces.
Mimeographing is another commercial application of stencil printing.

13. • Photocopying is where you make a photocopy of and
original image using a photocopier. There are many
advantages for using this like making copies of the original
for an office group or a school class. There are
disadvantages such as anyone can copy any image and
some of the text on the copy might be missing due to the
drum on the photocopier.

14. • Laser printing is an electrostatic digital printing process that rapidly
produces high quality text and graphics by passing a laser beam over a
charged drum to define a differentially charged image. The drum then
selectively collects charged toner and transfers the image to paper,
which is then heated to permanently fix the image. As with digital
photocopiers and multifunction printers (MFPs), laser printers employ
a xerographic printing process, but differ from analog photocopiers in
that the image is produced by the direct scanning of the medium
across the printer's photoreceptor. Hence, it proves to be a much faster
process compared to the latter.

15. • Inkjet printing is a type of computer printing that creates
a digital image by propelling droplets of ink onto paper,
plastic, or other substrates. Inkjet printers are the most
commonly used type of printer, and range from small
inexpensive consumer models to very large professional
machines that can cost tens of thousands of dollars, or
more.

16. • Desktop publishing (abbreviated DTP) is the creation of
documents using page layout skills on a personal computer.
Desktop publishing software can generate layouts and produce
typographic quality text and images comparable to traditional
typography and printing. This technology allows individuals,
businesses, and other organizations to self-publish a wide range
of printed matter. Desktop publishing is also the main reference
for digital typography. When used skilfully desktop publishing
allows the user to produce a wide variety of materials, from
menus to magazines and books, without the expense of
commercial printing.