Sunday 20 October 2013

Screen printing: A guide to

Screen printing is a brilliant printing technique for bold, solid, stylized designs. In its most basic form, it is composed of three layers: a substrate as the base (card, fabric, vinyl, etc.), a stencil in the middle, and a woven mesh screen on top. Additional equipment required are a squeegee, thick paintbrushes, screen printing ink, and textile medium.

And now, a simple step-by-step on the process.

1. Draw your stencil. A stencil should ideally be made using something thicker and stronger than printing paper or newsprint paper; card or cartridge paper is what you should go really go for. Remember that only the only the outlines are necessary, so make them nicely opaque/bold.

2. Cut out your stencil. Where shapes in the stencil have 'holes' in the inside, cut the holes out separately and retain them for future use. Alternatively, connect these think of these holes as 'islands'. In other words, leave at least two strips of material connecting the hole with the rest of the main body of the stencil unless you want it intentionally otherwise.

3. Set up the equipment. The substrate goes at the bottom, the screen on the top, and the stencil sandwiched in between. Ensure that the stencil covers at least the entire area of the mesh of the screen. If it does not, use masking tape to cover up smaller gaps or prepare additional pieces of paper/another substitute to cover larger gaps. This is to avoid ink being applied to anywhere other than where the cut out areas on the stencil are.

4. Prepare the ink: I. On a separate surface to the screen sandwich, lay out the colour palette to be used. To each one, apply a proportional amount of textile medium to make them easier to work with; this paint to textile medium ratio should be about 60:40. Use thick paintbrushes to blend each colour with its allocated textile medium.

5. Prepare the ink: II. The ink should be applied in a line on the top of the mesh screen and span the entire width of the screen. For multiple colours, divide this line into the selected colours scheme; make sure that they overlap of a gradient is required.

6. Apply the ink. Grab the squeegee and dab it into the line of ink. Then, for the neatest results, ensure that someone or something has secured the screen down onto the work surface tightly. Firmly grip the squeegee and pull it downward to cover the entirety of the stencil. You should hold the squeegee an angle of roughly 60°, using only the edge of the blade. When correctly done, a kind of 'smooth' scraping sound will be produced by the squeegee.

7. Repeat. Once the stencil is covered after the first application of ink, lift the squeegee off of the screen and proceed the to dab it again in the store of ink at the top of the screen, this time with a little more force to remove the excess. Again, pull the squeegee down across the stencil as described above and repeat this once or twice more. It is especially important that the placing of the squeegee on these repeats is consistent if multiple colours are being used, in order to avoid unintended mixing of the colours. 

8. Hey presto. Lift the screen and stencil together slowly to reveal the result on the substrate. The first attempt will (almost) never be perfect, however by understanding where improvements can be made, it is easy to refine the technique.

9. Try another substrate. Screen printing is great for reproducing the same designs over and over again. A piece of card of another colour or maybe even a new material altogether, can be placed underneath the stencil and steps 5 through to 8 can be repeated for this new substrate.

10. Wash up. Due to the sheer amount of ink and textile medium used, thoroughly clean the mesh screen and other equipment and to aid their longevity and re-usability.

I believe that this type of printing is most suitable for designs with large, bold shapes as opposed to those with a heavy amount of line art or smaller details. It appears that my technique still requires some refining as the gradients do not appear to be entirely consistent with successive prints, which tells me that I should be more careful with the placement of the squeegee. In addition, in the future I could create stencils which retain the 'islands' in order to experiment with the different style that would produce.






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