Screen printing, also known as serigraphy or silkscreen printing, is an ancient technique used to produce imagery (‘seriagraphs’). It was invented in China around two thousand years ago.
Traditionally, screens were made from silk stretched tightly over a wooden frame – hence the names silk screen and serigraphy. (Seri- comes from the latin sēricum – referring to Chinese goods, and especially silk, and -graph meaning ‘write’ or ‘written’.)
Silk was used due to its fine weave, which allows a good amount of ink to pass through the tiny holes when it’s pulled across the surface using a squeegee. Nowadays synthetic materials such as nylon are used for making printing screens.
The material stretched across the frame, also referred to as the mesh, is then transformed into a stencil.
What is a screen printing stencil and how do you make one?
A screen printing stencil allows you to define the lines and chunks of colour you want to appear in your image. A stencil is created by blocking parts of the mesh so that ink can’t pass through, leaving other parts open. A squeegee is used to evenly pull ink across the screen. The ink passes through the open parts of the mesh and onto the surface underneath.
Using the same stencil, or a new one, you can build up your image, layering colours over one another. The more transparent the ink (for water-based inks, this means using more water used when mixing ink), the more the colour below will show through. In this way colours can be layered to create new colours.
When using thicker, quick drying inks, such as acrylic paints, a transparent medium added to the ink slows the drying, giving you more time to use the screen before the ink dries and blocks the mesh.
There are many ways to make a stencil from your screen. They fall into three main categories:
- Hand-cut stencils: Cut stencils from a thin sheet of paper, film or plastic then place between your screen and the surface you want to print on
- Photo stencils: Coat your screen with photosensitive emulsion then expose the screen along with your design using UV light
- Hand-drawn stencils: Draw directly onto the mesh with a wax crayon to block certain areas, or use drawing fluid to paint your design directly onto your screen
Each of these techniques need lots more explanation and will be covered on the Utrecht Print Exchange blog soon… Sign up to receive our updates via email to keep in the loop!
How many times can a screen be used?
A screen can be used multiple times with different stencils applied and cleaned off again. It will only need to be replaced if the mesh rips or the screen becomes irreversibly blocked.
Multiple stencils can be used for each design – often one stencil is used for every new colour or layer of the design (unless you’re making a monoprint – more on that coming soon).
If you’ve never screen printed yourself, reading a description of the technique can make it all sound more complicated that it actually is. Seeing the process in action and doing it yourself is the key…