1.5 Paper and board printing processes Flashcards
What are the 4 Paper and board printing processes
Offset lithography, digital printing, flexography, screen printing
What is the process for screen printing
Ink is squeezed through a fine mesh to leave a printed image, with an emulsion blocking the mesh in non-image areas.
A different screen is required for each colour.
What are the 3 adv and 2 disadv of screen printing
-Lower costs mean unique one off products and batches are viable
-Ability to print onto a range of different surfaces and materials that couldn’t be put through a printing press
-Ability to use specialist inks”Glow in the dark”
-However it is a time consuming process
-And not photographic quality
What paper and board printing process could make T-shirts, posters, promotional merchandise
Screen printing
How is an image transferred to the screen in screen printing
An acetate stencil is printed with the image areas in black (film positive).
A fine mesh screen is coated with UV light sensitive emulsion and the stencil is placed on the screen and exposed to UV light.
The UV light hardens the emulsion but not in the areas where the black stencil covers the emulsion.
The screen is washed to remove the unhardened emulsion (image areas)
How can you Increase production rates for paper and board printing
Printing on cylindrical objects
e.g. bottles and mugs
High speed printing on rolls
of material e.g. wallpaper
In flexography what is the Raised image/relief-type flexible printing plate/sleeve attached to
Plate cylinder
What is the 4 colours for printing
CMYB, Cyan, magenta, yellow, black
What are the 6 elements for flexography
Ink pan, fountain roll, Anilox roll, Plate cylinder, Impression cylinder, Substrate(roll of paper)
What in part of flexography has laser engraved ink cells to store and transfer ink
Anilox roll
What paper and board printing process could make Carrier bags, wallpaper, labels & packaging
Flexography
What are the 2 adv and 2 disadv of offset lithography
+Batch to mass production
+Print quality is very good
-Not suitable for short print runs due to time and costs
-Limited to materials that can be put through a printing press as sheets or in rolls
What are the 5 steps for offset lithography
- Printing plate fixed to plate cylinder
- Rollers apply damping solution to non- image areas of plate
- Rollers apply ink that only adheres to emulsion (image areas)
- Offset/rubber blanket cylinder removes some water and transfers image to the paper
(also helps extend plate life) - Impression cylinder to keep paper in contact with blanket cylinder
What are the 2 adv and 3 disadv of flexography
-A wide variety of surfaces can be printed, including delicate and textured ones
-High speed for mass production
-Print quality is good
-However is not suitable for short print runs
-And is limited to materials that can be fed through a printing press in rolls
What paper and board printing process could make Books, magazines, posters & packaging
Offset lithography
