Printing processes

Question 1

describe the process of offset lithography

Answer 1

• UV light is used to transfer the image onto a smooth aluminium printing plate
• the image area is coated with a chemical that attracts the oily ink but repels the water (so non-image area holds water)
• the image is printed onto a rubber blanket cylinder which squeezes away the water+leaves the ink/image behind
• the ink is transferred onto the paper between the blanket cylinder and an impression cylinder

Question 2

describe the uses & benefits of offset lithography

Answer 2

• fast and high-quality finish
• good for print runs of 1000+ copies
• books, newspapers, magazines, packaging

Question 3

describe the process of flexography

Answer 3

• a flexible rubber/plastic printing plate holding the image (sticks out a bit on the plate) is applied to the surface with an impression cylinder underneath

Question 4

describe the uses & benefits of flexography

Answer 4

• can be used to print onto surfaces that aren’t completely smooth
• quicker than lithography and the printing plates last longer
• used for large print runs 5000+
• cardboard, plastic bottles, packaging, wallpaper, carrier bags

Question 5

describe the process of screen printing

Answer 5

• a stencil is put under a fine mesh screen
• ink is spread over the top of the mesh screen using the blade
• ink goes through the stencil and is printed onto the material below

Question 6

describe the uses & benefits of screen printing

Answer 6

• low cost - ideal for short print runs 100-300 where detail isn’t needed
• can be used to print on various surfaces
• posters, estate agents signs, textiles, t-shirts

Question 7

describe the process of dry/digital printing

Answer 7

• a design is sent from a computer
• the printer recognises required colours and adds layers of cyan, magenta, yellow, and black (CMYK) to make the final colour

Question 8

describe the uses & benefits of dry/digital printing

Answer 8

• less fiddly than printing plates, no set-up costs apart from buying the printer + ink
• is expensive per sheet but is cheaper for short print runs around 100 copies
• posters, flyers, digital photos