Relief Printmaking – Screen printing

Introduction

This module covered the penultimate method in Susan Yeates’ online “Introduction to Printmaking” course. The module considered three methods of screen printing:

  1. First method using simple stencils created using any flat material or paper that will block the ink including fabric, ribbon, leaves, string and paper.
  2. Second method using hand-cut stencils prepared from acetate sheets or paper. The stencils need to be as thin as possible to prevent a halo effect appearing around the printed area.
  3. Third method uses liquid fillers to create a stencil directly on the screen.

As I found the first two methods frustrating to use (for example, using acetate as a stencil created the halo-effect (see Image 1 at the end of this blog) and using thinner materials resulted in the stencil pulling away from the screen and sticking to the print paper) I will describe the third method together with the way the screen should be set-up and how the inks should be used.

Images 2 to 6 below are examples using different types of stencil.

Tools and Materials

The basic tools of screen printing include the following:

  • Screen
  • Screen bed / area to work
  • Squeege
  • Printing inks
  • Paper

Screen
This is a wooden or aluminium frame with a fabric mesh stretched very tightly over it. Screens come in different sizes and with different mesh counts measured in threads per centimetre. A screen with a mesh count of 120T (i.e. 120 tiny openings between each thread) is much finer than a screen with a count of 60T. A screen of 120T is useful when carrying out very fine work such as photographic work and 60T for work using large flat areas of colour.

I used a small wooden-framed screen with a yellow mesh and a mesh count of 90 threads per centimetre (90T). The external size of the frame was 47cm x 33cm and the screen area 38cm x 24cm. A larger screen would have given me more opportunities; the small version was constrictive to a degree.

Screen bed
I constructed a screen bed using a sheet of MDF that was longer and wider than the screen. When printing from home a simple MDF / plywood board or a wooden table as the base and some hinges or clamps to fix the screen at the back so you can lift it will do.

I then attached a length of wood the same height as the wooden screen frame to the screen bed and attached a pair of hinges to the edge of the frame and the wood so that the screen can be lifted up and down with ease. The hinges have a small metal pin that can be removed from the centre so that the screen can be detached for cleaning.

Squeegee
The squeegee consists of a rubber blade fixed into a wooden handle. This tool is used to push the ink through the mesh on the screen. Again squeegees come in different sizes and the rubber blades come in different softnesses. As a general rule, the squeegee should be narrower than the screen so that it fits comfortably into the inside of the frame with a few inches either side. It is also useful to have a smaller squeegee available for pulling smaller amounts of ink through the screen.

Print inks
Either water-based or oil-based inks can be used in screen printing; however, water-based inks have the advantage that they are non-toxic, easy to clean up and do not require strong chemicals such as turpentine to remove them. I used the Speedball System of inks during this method.

Paper
Similar quality paper can be used for screen printing as any other process. Again a smooth surfaced paper will work well with the flat even colour pushed through the screen.

Process

I will concentrate on the direct stencil method using liquid filler. Having drawn a design on paper, tape it on the screen bed, centred on the clean screen. Parcel tape is applied to the edges of the screen leaving an area in the middle the size of the print.

Using a soft pencil trace out the design for the first colour directly onto the mesh. Be very careful to use a soft pencil and only press very gently as a sharp pencil pressed hard can damage the screen.

When the tracing is finished, prop the screen up an inch or two and, using the drawing as a guide, apply a water-based screen drawing fluid (screen filler) with a suitable paintbrush. Where the drawing fluid is applied is where the print will occur.

When the fluid is completely dry, use a palette knife to apply some screen block to the top of the screen above where the filler was painted.

Using a squeegee drag the screen block down the screen in a similar manner to pulling ink down the screen. As the screen block is a more oily/waxy substance, it will block the mesh where the drawing fluid has not been applied.

With cold water and a sponge begin to gently wipe the mesh. The screen drawing fluid is water-soluble and will gradually wash away. The screen block will remain in place as it is only soluble with hot soapy water. Keep wiping until the drawing fluid is completely removed. This will leave just the screen block on the mesh. This is the stencil and, once dry, is ready to print.

Prepare several sheets of printing paper all the same size. Thick smooth paper works best as it will not crinkle when a large flat area of ink is printed. Have a few sheets of cartridge paper or newsprint paper to use for proofing first.

Choose and prepare you first colour ink and place a sufficient amount at the top of your screen using a palette knife. Lift the screen and place a sheet of cartridge paper underneath the screen. Mark its position with some small pieces of card held in place with masking tape. This will mark where the printing paper is to be placed each time. Fix this sheet down with some masking tape at the edges to stop it from moving.

Regardless of which of the three methods are used, the screen should be flooded with ink by dragging the squeegee down the screen and back again at a 45 degree angle whilst the screen is still lifted from the paper. This will coat the mesh with ink ready for printing and also prevent the ink from drying on the mesh.

Then lower the screen down onto the printing paper. Take the print by pulling the squeegee down towards you to the bottom of the mesh using both hands to apply a firm and even pressure. The squeegee should be at a roughly 45 degree angle. This motion is forcing the ink through the screen onto the paper underneath. The ink will be stopped from touching the printing paper by the screen block that is on the mesh.

Once the print has been pulled, lift the screen up slightly and flood the screen with ink to prevent it from drying on the mesh. The sheet of paper with the printed image can be removed and left to dry. Fix the next sheet of paper in the same place ready for printing.

Take a second print (which will be identical to the first) by pulling the squeegee down the screen again. Continue to do this until all the pieces of paper have been printed.

When printing the first colour has been finished, scrape any excess/unused ink from the screen. All traces of ink can be removed from the screen by washing the screen down with a sponge and water. Any other tools can be cleaned at the same time. See Image 7 for the final print.

Conclusion and Comments

Whilst I enjoyed the direct method (with liquid filler as the stencil), I found screen printing to be generally unsatisfactory. Quite possibly, I will return to the direct method in future but would either prefer to use a larger screen for my studio use or attend a print studio that is fully equipped with large vacuum screen beds. One example is the West Yorkshire Print Workshop based in Mirfield, Huddersfield (www.wypg.org). The WYPG also provides a wide variety of courses.

Recommended Reading

Adam, Robert and Robertson, Carol (2014) “Screen Printing – the complete water-based system”. Published by Thames and Hudson Limited, London. [ISBN: 978-0-500-28425-4]

Image 1: Heart, Yellow on Red. Observe the ‘halo’ effect around the heart. In addition, the red ink has crept into the margin area. Although this was masked with parcel tape, the ink still squeezed under.
Image 6. Wheal Prosper Mine, Cornwall. Four colours on white paper using separate acetate stencils.
Image 7: Leaves. Two-colour screen print using the direct stencil method. To my mind, this was the opposite to linocut where you remove material rather than adding masks.