Question 3
(a) Explain the following terms, as applied to lithographic printing:
(i) contact printing;
(ii) basic exposure.
(b) State three factors to be considered when drawing the layout plan of a printing job.
Observation
Many of the candidates who attempted this question could not state three factors to be considered when drawing the layout plan of a print job. In all the candidates’ performance in this question was fairly okay.
The solution is a stated below:
(A)
(i) Contact printing: This is the process of exposing a sheet of light sensitive material by passing light through a previously exposed and developed piece of film. It is a method of converting negative to positive film or positive to negative film.
(ii) Latent Image: This is the appearance of faint images on the light sensitive material after it has been exposed to light . the image become visible when ever they are developed.
(iii) Basic Exposure: This is the camera aperture and shutter speed combination that will produce a quality film image of normal line copy with standardized chemical processing.
(B) Factors to be considered when drawing the layout plan of a printing of a printing job
- The size of the pages.
- The number of pages of the job.
- The machine type size.
- The size of plate.
- The methods of imposition required.
- Type of finishing operations.