OFF-SET LITHOGRAPHY

PRESENTATION BY:

IMPRAIM – SWANZY ENOCK

Graphic Design Tutor @ Ahantaman Girls’ Senior High Sch.

Email: eimpraimswanzy@yahoo.com

Meaning

Litho means stone and Graphy means writing or drawing

Off-set – is a printing process using ink transfer

It is a method of printing in which inked impressions are transferred onto paper from another surface

Lithograph is a picture printed using a stone or metal block on which an image has been drawn with thick oily substance that attract ink

Off – set Lithography

Is a method of making prints from a flat surface usually a stone or metal plate

In off-set lithography, the printing surface (substrate) and non-printing surface are on the same level

Lithography is based on the fact that grease and water do not mix

GREASE

WATER

A German printer called Alois Senefelder in 1796 discovered this principle.

1771 1834

Making a lithographic print

To make a lithographic print, the artist first draw the image on the stone with grease based lithographic crayon.

The stone is treated with a light acidic bath to fix the image and soaked in water.

The water is absorbed by the stone only in the areas not coated with grease and repelled by water soaked background areas.

• Paper is placed on the stone and the pressed gently with the roller for the image to be transferred onto the paper.

• Remove paper after the image is transferred.

• Allow it to dry.

Off-set lithographic machine (printer)

The off-set lithographic machine operate in five systems

1. Feeding system

2. Dampening system

3. Inking system

4. Printing/impression system

5. Delivery system

The Printing press

We have three major procedures. These are:

PRE – PRESSDESIGNINGFILMINGPLATING

PRESSPRINTING

POST - PRESSPRINT FINISHINGCOLLATINGBINDING/STITCHINGGLUEINGTRIMMING

Equipments at the press

PAPER CUTTING MACHINE IMAGE SETTER

PLATE MAKEROFF-SET PRINTING MACHINE

STITCHING MACHINE

LASER JET PRINTING

SCANNER

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