Pre-press

Question 1

How does colour separation work?

Answer 1

The printer separates the colours into four process colours. The colours are separated using a colour separation computer program before the colours are printed as dots with varying depths to create tone.

Question 2

Four process colours are used for…

Answer 2

Higher clarity.

Question 3

What does the K in CMYK stand for ?

Answer 3

Key, as black adds more depth to the images so it is the key colour.

Question 4

The image is printed in dots. The greater amount of dots per inch, (dpi), means…

Answer 4

A better image quality and better clarity. A low dpi is used for newspapers, (around 200).

Question 5

What quality control methods are used ?

Answer 5

Registration marks.
Colour bars.
Crop marks.

Question 6

How do registration marks work ?

Answer 6

Most print processes have a plate for each colour. These need to align or else the image will be out of focus. The printer adds registration marks to check alignments. The mark should be the colour of the last ink used.

Question 7

Colour bars. How do these work?

Answer 7

They are added to ensure the colours are perfect. The bars show the densities or tints, (in percentages), of the individual colours. A densitometer then looks at the colour bar before adjustments can be made !

Question 8

How do crop marks work?

Answer 8

They tell the guillotine where to cut with 3mm left as a bleed area to allow for misalignment when cropping happens. The printed image is always larger than necessary for tolerance of error.

Question 9

What are special colours ?

Answer 9

These are pre-mixed colours that CMYK can’t make, such as fluorescent, (DayGlo), or metallic.

Question 10

Different print methods are used due to…

Answer 10

Variation in surfaces.
Quantities of prints.
Quality of the print.
Cost.

Question 11

Summarise the qualities of offset lithography.

Answer 11

Uses : newspapers, books, and magazines.
Positives : good quality print, fast, most common, prints onto paper well. 
Disadvantages: expensive to set up.
Cost: 5
Print quality: 9

Question 12

Summarise the qualities of flexography.

Answer 12

Uses: packaging, corrugated boxes, shopping bags, 3D surfaces. 
Advantages: fast.
Disadvantages: expensive set up.
Cost: 6 
Quality: 8

Question 13

Summarise the qualities of screen printing…

Answer 13

Uses: short print runs, T shirts, and posters.
Advantages: can print on absorbent surfaces, good for short runs.
Disadvantages: not as good quality- slow.
Cost: 4
Quality: 6

Question 14

Summarise the qualities of gravure…

Answer 14

Uses: high quality magazines and stamps.
Advantages: good quality, very fast.
Disadvantages: expensive set up costs.
Cost: 8 
Quality: 10

Question 15

Summarise the qualities of laser…

Answer 15

Uses: one-off items.
Advantages: immediate printing, no set-up costs.
Disadvantages: very expensive individual print.
Cost: 10
Quality: 7

Question 16

What are the plates for flexography made from?

Answer 16

Rubber.

Question 17

What are the plates for offset lithography made from?

Answer 17

Aluminium.

Question 18

How does checking the artwork work?

Answer 18

Artwork is checked to make sure the fonts, colours, and picture qualities are suitable.