Key Stencil

Colour Stencils

Setting up for Printing, Equipment & Materials

Printing Sequence

© Teresa Jordan 2006

This tutorial presumes a basic level of experience in screen printing.

Description

• “Grace” , Screenprint, 18cm x 18cm, 2006
  An edition of 12 screen prints.  The image was inspired by Grace Cossington Smith's painting:The Lacquer Room and was first rendered as a lino cut.
  The screen print has 5 'permaset' colours. Black is the key colour and masks the registered edges of the other colours, red, beige, transparent green & a very transparent blue. The red & green are overlayed in places to create a 6th colour (dark brown).

1. The key stencil

• The Key Screen was designed first but printed last
• I scanned my original black and white lino print* and resized it to fit an A/4 sheet. 
• I added registration marks and printed the image on my inkjet printer.
• At Officeworks I had it photocopied on a clear cell (OHT)
• I used this clear cell to expose a photosensitive screen
• Screens can be given a coating of photo emulsion and exposed commercially but I use Ulano925WR . I prepare a screen according to the instructions and then expose it to full sun for about 20 seconds. For more information on doing this yourself, try this website. http://en.wikibooks.org/wiki/Screen_Printing/Making_the_Stencil/Photo_Emulsion
• My favourite text on the subject is: Screenprinting, The Complete Water Based System by Robert Adam & Carol Robertson, Thames & Hudson 2003.

* I could have printed the lino straight onto acetate and used this as my key stencil.

2. The colour stencils

Registration Marks

Paper Cut Regos

• I designed the colour separations by computer but I could have worked from a coloured sketch registered to my inkjet print or my original lino-print.
• I cut paper stencils to print blue & beige. The shapes were simple enough for paper pickup technique (which is of course a lot cheaper). I did this by:
• Centering an A/2 sheet of thin bank paper over the smaller B&W inkjet print. I traced the shapes I wanted to print. I cut these shapes away.
• I made a simple paper pickup version of the registration marks by cutting tri-angles between the horizontal and perpendicular lines (see diagram on left).
• The small edition number meant that I did not have to strengthen the bank paper with shellac, contact etc. This meant easier printing and cleaner edges (no shadow)
• I created black and white versions of the masks I would need to print red and green and had clear cells of these photocopied as with the Key stencil. I exposed these transparencies side by side onto a second screen. (I could have created these by hand using acrylic paint to ‘block out’ acetate)

3. Setting up for printing

• I prepared 16 sheets of hand torn stonehenge 250 gsm acid free paper and a few cartridge ‘spoil’ sheets. Because a hand torn edge is difficult to register I used removable sticky tape to attach some old business cards at the bottom right & at the lower middle of each sheet to create 'hard edges'.
• I positioned & taped a copy of the key cell on one of the sheets. This became the ‘key’ sheet.
• I made registration tabs out of masking tape and positioned them on the base board to line up with the 'hard edges' of the key sheet.
• I hinged a screen in place & aligned the paper pick-up stencil's registration marks with those of the key sheet.
• After masking out the registration marks on the paper pick-up stencil, I was ready to print my first colour. I left the key sheet in place when proofing each of the Paper Pick-up stencils but removed it for photostencils.

4. Printing Sequence

1. I printed the light brown through a paper-pickup stencil using a 60T mesh screen, (screen A). The colour was made using permaset printing paste lightly pigmented with red, yellow and a small amount of blue. (I mainly mix colours by eye but if in doubt, follow a process colour chart).
2. After wiping & drying Screen A, I printed the second colour using a Paper Pick-up stencil which was again registered to the key sheet. (Remember to mask out each stencil's registration marks before printing.)
3. Screen A was then washed, dried, coated with emulsion and later exposed using the Key cell (for the black stencil). It was set aside for printing last.
4. I had previously exposed a second screen, (Screen B) laying the photo cells for the green & red stencils side by side.
5. I masked off the red area. I carefully repositioned my key sheet & registration tape and printed with green ink diluted by printing paste.
6. After washing the screen I reset the registration, masked off the green area and printed red at full strength.
7. Finally I printed in black using the key stencil. The black is opaque and the stencil image was designed to cover very slight variations in registration of the other colours in order to produce a clean border.