Screen printing process involves transferring a stencilled design onto a flat surface using a mesh screen, ink, and a squeegee. Most common surfaces are fabric and paper however with the use of specialised ink it is also possible to print on wood, medal, plastic and even glass. The basic method involves creating a stencil on a fine mesh screen, and then pushing ink (or paint, in the case of artwork and posters) through to create an imprint of your design on the surface beneath.
“Silk Screening” or “Silk Screen Printing” are the terms that are sometimes being used to describe screen printing. The actual printing process is very similar, but the way actual stencil is created can vary, depending on materials used.
Different stencilling techniques include:
Designs made using the screen printing technique may use just one shade of ink, or several. In the case of multicoloured items, the colours must be applied in individual layers, using separate stencils for each ink.
First step we take is printing the design to a transparent acetate film. This will be then used to create a stencil which is a foundation for any screen printing process.
Depending on complexity of design and the texture of the fabric, the printer will choose the mesh screen that is most suitable for the purpose. The mesh screen is then coated with a layer of light-reactive emulsion, which will harden when developed under bright light.
The bright light is the key. Acetate sheet with design is laid onto the emulsion-coated screen where both are exposed to very bright light that hardens the emulsion. This then allows the parts of the screen with the design to remain in liquid form.
If the final design is going to include more than one colour, then a separate screen must be used to apply each layer of ink. To create multi-coloured products, the printer must use his skill to design each stencil, and line them up perfectly to ensure the final design is seamless.
After exposing the screen to bright light for set time, the areas of the screen not covered by the design have turned hard. Any excess of emulsion is then carefully rinsed away. At this stage, the imprint of the design on the screen is ready for the ink to pass through.
The screen is then dried, and the printer will make any necessary touch-ups or corrections to make the imprint as accurate as possible to the original design. The stencil is now ready to be used.
The screen is then placed on the printing press. The item or garment being printed is laid down flat onto the printing board, underneath the screen.
There are a number of different presses, including manual and automatic styles, but most modern commercial printers will use an automatic rotary carousel printer, as this allows several different screens to work at once. For multicoloured prints, this sort of printer can also be used to apply the separate colour layers in quick succession
The screen is lowered down onto the printing board. Ink is added to the top end of the screen, and a squeegee is used to pull the ink along the full length of the screen. This presses the ink through the open areas of the stencil, imprinting the design on the product underneath.
If the printer is creating multiple items, then the screen is raised, and a new garment is placed onto the printing board. The process is then repeated.
Once all the items have been printed and the stencil has served its purpose, the emulsion is removed using a special washing fluid so the mesh can be reused to create new stencils.
