T&I Task 7.

Paper, Print and Printers

 

Paper

Photo Paper – Glossy, Matte, Pearl, Silk, Lustre.

 

Matte paper is a duller less shiny look as it diffuses more light off the surface, whereas a glossy or shiny paper will refract or reflect the light more directly to the viewers eye.

Photo Rag – moe cotton based – more fibre visible in paper, ussually a natural finish

Cartridge – usually used for watercolour painting, highly visible fibre base to paper

Cotton paper – even more fibre visible than cartridge, made using cotton as well as paper.

Baryta paper is excellent quality for B&W tonal ranges as made with Barium Sulphate.)

For darkroom paper, the above is available to be obtained some with a resin coat and others fibre based.

 

Resin coated is much quicker to use as only takes 8 minutes from initial development to the print being dry, whereas Resin coated which will give a better wuality of print takes 1 & 1/2 hours to dry per print.

Printing

What is a Printer?
A printer is an electromechanical device which converts the text and graphical documents from electronic form to the physical form. Generally they are the external peripheral devices which are connected with the computers or laptops through a cable or wirelessly to receive input data and print them on the papers. A wide range of printers are available with a variety of features ranging from printing black and white text documents to high quality colored graphic images.
Printers : Daisy Wheel, Dot Matrix, Inkjet Printers & Laser Printers

Quality of printers is identified by its features like color quality, speed of printing, resolution etc. Modern printers come with multipurpose functions i.e. they are combination of printer, scanner, photocopier, fax, etc. To serve different needs there are variety of printers available that works on different types of technologies.

Daisy Wheel Printers
Daisy wheel printers print only characters and symbols and cannot print graphics. They are generally slow with a printing speed of about 10 to 75 characters per second. By 1980 daisy wheel printers were the dominant printers for quality printing but since the prices of laser and inkjet printers have declined and quality of dot matrix printers has been improved, the daisy wheel printers are now obsolete.
Daisy wheel printers - working
Working of daisy wheel printers is very similar to typewriters. A circular printing element (known as daisy wheel, shown in the below image) is the heart of these printers that contains all text, numeric characters and symbols mould on each petal on the circumference of the circle. The printing element rotates rapidly with the help of a servo motor and pauses to allow the printing hammer to strike the character against the paper.

 

Laser

Laser Printers
Laser PrintersLaser printers are the most popular printers that are mainly used for large scale qualitative printing. They are among the most popularly used fastest printers available in the market. A laser printer uses a slight different approach for printing. It does not use ink like inkjet printers, instead it uses a very fine powder known as ‘Toner’. Componetns of a laser printer is shown in the following image:
Working of laser printers, components of laser printers
The control circuitry is the part of the printer that talks with the computer and receives the printing data. A Raster Image Processor (RIP) converts the text and images in to a virtual matrix of dots. The photoconducting drum which is the key component of the laser printer has a special coating which receives the positive and negative charge from a charging roller. A rapidly switching laser beam scans the charged drum line by line. When the beam flashes on, it reverses the charge of tiny spots on the drum, respecting to the dots that are to be printed black. As soon the laser scans a line, a stepper motor moves the drum in order to scan the next line by the laser.
A developer roller plays the vital role to paste the tonner on the paper. It is coated with charged tonner particles. As the drum touches the developer roller, the charged tonner particles cling to the discharged areas of the drum, reproducing your images and text reversely.  Meanwhile a paper is drawn from the paper tray with help of a belt. As the paper passes through a charging wire it applies a charge on it opposite to the toner’s charge. When the paper meets the drum, due to the opposite charge between the paper and toner particles, the toner particles are transferred to the paper. A cleaning blade then cleans the drum and the whole process runs smoothly continuously. Finally paper passes through the fuser which is a heat and presser roller, melts the toner and fixes on the paper perfectly.
Photo Printer – These inkjet printers are color printers that produce photo lab quality pictures on photo papers. Although they can also be used to print documents but they are specially designed for printing the photo. They have a large number of nozzles that can print very fine droplets to enhance the image quality. They can print a 4 x 6 inch photos directly from the digital cameras without need of a computer. 
Dye Sublimation Printers – These are latest innovative printers that are specially designed for high quality photo printing. They magnetize the ink over a charged paper to produce a very high quality picture. These printers are suitable to photo hobbyists but are a quite expensive.
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