Prior to the invention of printing, documenting or recording information was administered by hand. Early examples would be of educated monks hand-writing out religious documents. To create multiple examples of the same copy would require many hours of labour.
The development of printing has made it possible for books, newspapers, magazines, and many other materials to be mass produced and played an important role in promoting literacy among the masses.
Printing is a process for reproducing text and images in a repeatable manner. There are many different techniques that have historically evolved. The following should provide you with a basic understanding.
With the introduction of computers there are now two distinctive families of printing techniques: Matrix and Non-Matrix
In print making, the matrix is whatever is used to hold an image, which is then charged with ink and used to transfer that image onto a substrate.
A simple example of a print matrix would be a potato that has been cut in a way where a shape the “sticks out” creating a “stamp” which when ink is applied to it enables repeat printing as shown in the images below
Traditional matrix based print making techniques fall into four categories:
With the development of computers it is now possible to print designs without
the use of a matrix as a computer can send instructions to a binary printing
machine with tells the print media what is required. That is, the computer
sends a message to an ink jet printer that tells the print head to either
deposit ink or not.
Non-matrix print techniques include: -
There are techniques that use combinations of the above where the first process is to print an image onto a “carrier” rather than directly onto the desired substrate. This “carrier” is then used to transfer the image onto its final destination. This is called “offset printing.”
Offset print techniques
These techniques will now be described in further detail.
Is a print making process where protruding surface faces of the printing plate or block are inked; recessed areas are ink free. Printing the image is therefore a relatively simple matter of inking the face of the matrix and bringing it in firm contact with the substrate.
Prior to the invention of computers the typewriter was developed as a method for speeding up the process of creating individual text documents and the letter stamps on the end of the hammer that impacted on an ‘inked ribbon” thus transferring the desired character onto the substrate is another example of relief printing.
Early computer printers used a dot matrix method where the letter & numbers were made up of a series of dots. This negated the use for individual letter stamps.
Is the family of printing and print making techniques in which the image is incised into a surface, and the incised line or sunken area holds the ink. It is the direct opposite of a relief print.
Normally, copper or zinc plates are used as a surface or matrix, and the incisions are created by etching, engraving, dry-point, aquatint, or mezzotint.
Due to these controllable plate-making methods, it is possible to create detailed high-resolution recesses in a matrix and therefore is widely used in modern day printing.
It is particularly suitable for use with rollers as well as plates.
Planographic printing means printing from a flat surface, as opposed to a raised surface (as with relief printing) or incised surface (as with intaglio printing).
The planographic process works on the basis that water will not mix with oil and the surface of the “flat” matrix is manufactured in a way where the desired print area holds the ink and the non-print area repels it.
Unlike the processes noted above where the ink is transferred from one surface to another, serigraph describes the technique where the ink is passed through a stencil.
The main commercial example of this technique is called SCREEN PRINTING
This is the main printing technique used here at TOT. Further information can be found by referring to Understanding Screen Printing Part 1 – The Stencil.
Non-matrix based print making techniques are only possible due to modern technology. Examples of these techniques are as follows: -
This
is a type of computer printing that reproduces a digital image by propelling
extremely small droplets of ink onto paper, plastic, or other substrates.
Inkjet printing is a non-impact form of printing, i.e. they do not touch
the paper when creating an image. Instead they use a series of nozzles
to spray dots of ink directly onto the paper.
THERMAL
This
is a digital printing process, which produces a printed image by selectively
heating thermal paper, when the paper passes over the thermal print head. The coating turns black
in the areas where it is heated,
producing an image.
LASER
This printing process uses a focused beam or light to transfer text and images onto paper. As paper passes through the printer, the laser beam fires at the surface of a cylindrical drum called a photoreceptor. This drum has an electrical charge (typically positive), which is reversed in areas where the laser beam hits it. By reversing the charge in certain areas of the drum, the laser beam can print patterns (such as text and pictures) onto the photoreceptor.
Once
the pattern has been created on the drum, it is coated with toner from
a toner cartridge. The positively charged toner clings to areas of the
drum that have been negatively charged by the laser. When the paper passes
through the printer, the drum is given a strong negative charge, which
allows the toner to transfer and stick to the paper.
PLOTTER
This
method takes an image from a computer and sends a message to a plotter,
which instructs the substrate to move across the X-axis and a knife or
pen across the Y-axis. A pen will draw the image onto the substrate. When
using a knife the substrate will have two layers – the carrier and the
vinyl. The knife will cut through the vinyl but not the carrier, enabling
removal of the unwanted part, known as weeding, from the image. This desired
image can then be heat transferred.
Offset litho printing, is a method of mass-production printing in which the images on metal plates are transferred (offset) to rubber rollers and then to the print media. The print media, usually paper, does not come into direct contact with the metal plates.
This printing technique can transfer a 2D image onto a 3D object. This is accomplished using an indirect offset printing process that involves an image being transferred with the use of a decal
Decal - definition
A decal is a substrate that has printed on it a pattern or image that can be moved to another surface upon contact.
This decal is the intermediate/transitional substrate, which holds the wet ink on a flat plane onto which a silicone pad is then pressed to pick up the image. When the pad is then pressed onto the substrate it wraps itself around and transfers the image to this chosen surface.
Heat transfer printing is a method of transferring a desired pattern via heat onto a substrate.
The required image can be produced onto a piece or paper (carrier) by any of the above means, using the appropriate ink.
Note: The image will be in reverse
Then take the transfer and with the application of heat, the ink will re-gel (melt), stick to the substrate and release from the paper.
Terms such as hot split, cold split and sublimation are all related to the heat transfer methods and will be covered in a later tutorial.
The heat transfer process can also be used to apply diamanté and foils – again these will also be covered in later tutorials.