Question 3
- (a)(i) Define Offset Lithography.
(ii) Give two merits of offset lithography.
(b) Explain the following terms used in lithographic printing:
(i) exporsure;
(ii) damping solution;
(iii) proof.
Observation
Solution
- (i) What Offset Lithography is
This is the planographic system of printing in which the image and the non-image areas are on the same plane.
(ii) Merits of Offset Lithography
The transfer of images from plates to blanket is easy.
Impression is more appropriately obtained in the method.
(b) (i) Exporsure
This is the subjection of printed documents to the required documental conditions for development and perfection. The condition includes, and not restricted to, humidity and light.
(ii) Damping Solution
This is the water-based liquid with balanced pH value, used at low temperature (between 4 oC to 8 oC) for the osmotic resistance of condensed water on substrate.
(iii) Proof
This is an impression of a print taken in print-making process for the purpose of noting current state of a plate while the plate is being worked on.