Secondary Research - Lithography

Lithography


Offset lithography is a process used for printing on a flat surface, using printing plates. An image is transferred to a printing plate, which can be made of a variety of materials such as metal or paper. The plate is then chemically treated so that only image areas will accept ink. Water and ink is applied to the plate. Because of the chemical treatment, ink only "sticks" to the image areas, which reject the water. Areas without images reject the ink. The plate is then rolled onto a rubber cylinder applying the inked area, and in turn the rubber cylinder applies the image to the paper. The system is "offset" because the plate does not come in direct contact with the paper, which preserves the quality of the plate.


How to do Lithography.


Step 1- Things You'll Need to make a lithograph: lithography pencil or crayon, lithographic ink, turpentine, limestone or metal plates, tale, rosin, sponge, gum Arabic, lithographic roller, lithography press, lithography paper.

Step 2- Using lithography pencils or crayons, reverse draw onto limestone/zinc/aluminum plate.

Step 3- Sprinkle rosin onto the plate to protect and then talc onto the image so that the chemical etch lies closer to the grease in the image.

Step 4- Apply the etch solution, gum arabic and nitric acid, to the stone and let sit for about an hour. Remove the drawing with solvent such as turpentine.

Step 5- Sponge the stone or plate down with water. Keep the stone's surface wet so that the ink only sticks to image areas.

Step 6- Load damp paper in the lithography press and then run through the press. The ink remains on the roller when it meets water and transfers from the roller when it meets the grease.

Step 7- When you lift the paper, you get a reverse print.

Step 8- Now print the final image!


Advantages & Disadvantages.

We are doing this stuff right The advantages of lithography are:
- It is very fast
- It does fast print runs
- It is cheap
- The images produced are clear and sharp

The disadvantages....
- It cannot produced very high quality prints
- It cannot do small print runs so people who want to print in small numbers cannot.
- The materials are complex to use.

These are both done through lithography. I like the really illustrative look of this. I like the use of both monochrome and the 3 colour process. Although you can see mega detail and can only see slight tones within the colour. Due to the drawing into the material therefore not high quality depending on your drawing. Which with my drawing probably would not be necessarily a good finishing for myself as I ain't a very good drawer.