Here is a brief history of the printing process
from the very earliest time to the present.
Definitions of the various processes follow
this section.
Tablets of stone carved with symbolic characters were used by the ancient Assyrians, Chaldeans and the Egyptians. Later, the Chaldeans made a form of clay tablet to replace the stone which was very heavy. The characters printed on these are known as cuneiform, or wedge-shaped, letters.
The Egyptians manufactured a crude kind of paper with the papyrus plant, a tall reed that grew along the Nile. The thin, fibrous layers underneath the outer skin were dried, flattened, then interwoven into a mat. It was then soaked, pressed and dried and became a sheet of papyrus on which writing could be applied with ink.
Heiroglyphics ("sacred-writing") done by the Egyptians and the picture-writing of the early American Indians are two most common forms of early graphic communication.
Printing from wood blocks seems to have originated in the Orient as early as the 8th century and brought to Europe by traders in the early days. In 1417, Jan de Printere of Antwerp made wood block prints and others followed his example.
The papyrus scroll was the forerunner of the modern book. Gradually the book form was developed, having folded sheets bound together. In 1456, Johann Gutenberg of Germany invented the first movable metal types for printing in his "Bible of 42 lines". It was a book of over 1300 pages printed laboriously by hand on a crude press 2 pages at a time.
Aldus Manutius (b. 1450) devoted his life to the task of improving the quality of printed books. He designed a new type face that later became known as "italic" as all the letters were slanted.
Nicolas Jenson developed the Roman letter into its finest form. It became the pattern for nearly all the printers of Europe.
Geofroy Tory (France, 1480-1532) and his pupil Claude Garamond brought out the first French type of distinction. Garamond came to devote his entire time to producing types for other printers and thus marks the beginning of the type foundry as a separate activity.
William Caxton introduced printing in England. But the best known printer of early England was William Caslon who operated a printing office and type foundry in the early 18th century.
Alois Senefelder (Bavaria) discovered in the late 1700's that reproduction of images could be obtained by drawing, painting, or transferring them with a greasy ink or paint of the smooth, porous surface of a certain limestone rock in his vicinity. This process came to be known as lithography. Greasy surfaces repelled the water, while the oily or greasy ink would not adhere to the moistened surface of the stone.
Engraving
The design to be printed is cut into a plate made of wood or metal. When the plate is
inked, the ink collects in the cut lines of the design; the rest of the plate is wiped
clean before printing. Requires the application of heavy pressure so that the paper can
actually be forced into the inked incisions. First used in Germany in 15th century.
Letterpress
The image is on a raised surface. It is the oldest printing process. The image areas are
raised and the non-image areas are below the surface. The type or plates are inked and
pressed into contact with the paper surface.
Offset Lithography
The difference between the image and non-image areas on the plates is maintained
chemically by the mutual repulsion of grease and water. The image are is covered with an
ink that is grease-receptive, and the nonprinting areas are made water-receptive. The
plate comes in contact with rollers wet with a water solution and rollers wet with ink.
The water solution wets the nonprinting areas so that the ink wets only the image areas
and then is transferred, or offset, to an intermediate cylinder covered with a rubber
blanket. The paper picks up the impression of the image as the paper travels between the
rubber-covered blanket cylinder and an impression cylinder.
Thermography
Means "heated printing". A means of raised-letter printing that simulates
engraved printing at less cost. Special oily, slow-drying inks are used for printing
conventionally by letterpress or lithography. The wet inks are then dusted with a fusible
powdered compound and excess powder is removed from the nonprinting areas by suction. The
sheet is then passed under a heater that fuses the ink and powder. Another type of ink
contains an agent that expands when exposed to heat.
Embossing
A process that creates a 3-dimensional image by placing a sheet of paper between a concave
and convex set of dies.
Diecutting
A process that uses a razor-sharp steel rule to cut or punch various shapes in the press
sheets.
Hot Foil Stamping
A process in which the relief type form is locked into a special chase which can be heated
while on the press. The ink rollers are removed from the press and replaced with a device
that holds a plastic ribbon in front of the type form. As an impression is made, the
heated type plus the pressure of the press during the impression causes the metallic color
from the ribbon to be transferred to the press sheet.
Educational Links
http://en.wikipedia.org/wiki/Spot_color
http://en.wikipedia.org/wiki/Process_color
http://en.wikipedia.org/wiki/Rgb