WATER-BASED SCREENPRINTING Techniques 1. Preparing the screen a. Attaching the screen   b. Taping the screen   c. Registration clips 1. Drawing fluid a. Tooth brush spray b. Brush c. Airbush d. Blot e. Texture f. Reed pen 2. Water soluble crayons (Payons) 3. Stencils a. Butcher-paper b. Contact paper 4. Screen Filler a. White line b. Tonal variations c. Texture d. Washing out the screen filler 5. Hunt Speedball Photo Emulsion 6. Printing the screen 7. Three color print Materials Polyester Screen 12XX Screen frame and base Cord Hunt Speedball Drawing Fluid Hunt Speedball Screen Filler Payons (water soluable crayons) Brushes Reed pen Tooth brush Two inch packing or duct tape Newsprint pad Gloves Mylar Paper - Arches 88 or Rives BFK Clean Up Materials Ammonia Soft Scrub Power washer Scrub brush The Screenprinting Screenprinting is essentially a sophisticated stencil method of printing. A simple stencil can be made by cutting a specific shaped hole in a piece of paper, a star shape for example. To print the star placed paper under the stencil and apply ink to the open area. The ink goes on to the paper beneath the stencil in the shape of the star. Screenprinting takes the process a step further. A fine polyester screen is attached to a frame. The screen can then be painted in some areas so that the pores of the screen are filled. The paint acts like the paper stencil to block the ink. The rest of the screen remains open like the star shaped hole in the paper stencil. A squeegee is used to print the screen by forcing ink through the screen and onto the paper.

SCOTT KOLBO               SCREEN AND BASE                                 PAINTED STENCIL

Preparing the Screen

1. Attach the polyester screen to the frame using the rope.

2. Place the screen over the back side of the frame, the side with the grooves cut into it.

3. Place the rope on top of the screen along the grooves. The rope should be cut to the length of the groove on each side.

4. Push the rope into the groove at the middle of each side. Work from one side to the opposite side the same way a canvas is stretched. As you push the rope into the groove the screen will be forced into the groove stretching it across the frame. Do not stretch it too tight. Push the cord into the groove only to the point where the rope is level with the surface of the frame.

5. Push the rope into the groove towards the corners evenly around the whole screen frame. No side should be stretched sooner than any other. Work from one side to the opposite side so the screen is stretched evenly.

6. Cut off the excess screen that extends beyond the edge of the frame.

Taping the Screen

1. When the screen is in place, stretched tight, and the edges trimmed, stick tape on the back of the frame over the rope and the groove. Duct tape or packing tape works well. Also stick tape along the inside of the frame so that half of it is on the screen and half on the edge of the frame.

2. In addition put a piece of tape in each corner. This will prevent ink from going between the screen and the frame and ruining your print.

3. Apply tape to the screen on both sides creating a picture plane or edge for your composition. (ten inches wide maximum on the small screens)

 Preparing to Work on the Screen

4. Attach the frame to the base board using the wing nuts.

5. Place the drawing under the screen. The paper that the drawing is on should be at least two inches larger than the image size.

6. Tape three registration clips to the backing board tight against the edges of your drawing, two at the top and one on the side. Line up the drawing so that it fits in the untaped opening of the screen. To make a registration clip cut a sturdy piece of paper one inch wide and three inches long. Fold the paper in thirds like an accordion.

7. Place a piece of mylar or acetate over the drawing so materials used to draw on the screen will not ruin the drawing.

8. Paper placed in the registration clips.

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Applying the drawing fluid

A. Use a brush, drawing nib, or reed pen to apply the drawing fluid to the screen. Make marks in as great a variety as you would in a drawing. Use the drawing fluid full strength. Check often to see that you are applying a sufficient amount to drawing fluid to the screen. Hold the screen up to the light and observe whether the drawing fluid fills the holes between the threads of the screen. If it does not those areas will not print, so put more drawing fluid in those areas. What you draw on the screen with the drawing fluid will print when the screen is inked.

B. A tooth brush can be used to flick the drawing fluid on in little dots. It is wise to use a stencil so the dots of fluid are not applied where you don't want them. Make the stencil out of a piece of paper. Simply cut a hole in the paper in the shape desired and place it on the screen.

C. Use a reed pen to draw lines on the screen. Use the fluid full strength. Do not sharpen the pen so much that it will catch on the screen fibers. Draw as you would with a pen on paper.

D. Textures can be created on the screen by apply the drawing fluid to a textured surface such as a sponge or cloth. Press the texture to the screen, and the drawing fluid will come off onto the screen. Test the texture on a piece of paper first to make sure the amount of fluid applied is just right. If there is too much fluid the texture will fill in and if there is not enough the texture will not transfer fully.

E. An air brush can be used to apply the drawing fluid. The air brush is used like you would when making a painting or drawing. As always, for the air brushed drawing fluid to be effective it must fill the holes in the screen. If only the threads are stained the work you are doing will not yield the results you desire. The drawing fluid must be thinned with water to work well in the air brush.

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Applying Screen Filler

After you have completed your work on the screen and are ready to print you must first apply screen filler over the entire screen. The screen filler acts as a stencil to block the ink in the printing process. The drawing fluid and water soluble crayon will lift the screen filler and open the screen wherever they were applied.

1. Remove the screen and frame from the base board. Place the screen frame on two boards so it is held off the table top. Pour a bead of screen filler across the top of the screen and scrap it along the screen using the squeegee. Pull firmly and steadily. Do not pull the squeegee across the screen more than once or the screen filler will build up too thick on the back of the screen. When the thick screen filler dries it will be hard to remove and the time spent on the drawing will be wasted.

2. Put the excess screen filler back in the jar and clean the squeegee and the inside edges of your screen and frame. Use water to clean the screen filler off of both. Do not waste the screen filler.

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Washing Out the Drawing

1. When the drawing on the screen is complete and the screen has been covered with screen filler it is time to wash out the drawing. Washing out the drawing will open the areas of the screen where drawing fluid and Payons were used, allowing ink to pass through in the printing process.

2. When the Screen Filler is completely dry take it to the sink and run water across it.

3. Use a scrub brush or tooth brush to help lift the screen filler in the areas where the drawn marks exist

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4. When all the drawn areas have been washed out, dry the screen. To be sure all the drawn areas are clear of screen filler hold the screen up to the light and inspect the pores of the screen to see that they are not clogged with screen filler.

4. If there are areas where the seven filler is stubborn and will not come out of the screen, use a tooth brush and ammonia diluted with water to scrub it out. Be careful not to scrub away screen filler in other areas though.

6. When the screen is dry hold it up to the light once again to see if any of the screen filler has lifted where you don't want it to. If you find pin hole or other areas wash out paint screen filler over them to correct the problem.

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Photo Emulsion Screen Print

Hunt Speedball Photo Emulsion is a ultra violet light sensitive liquid that can be used to put both drawn and photo images on a screen. A scoop coater is used to apply the emulsion to the screen. When the emulsion is dry a positive transparency is placed on the screen and UV light is used to expose the emulsion. When the light strikes the emulsion, it hardens it. The dark positive portions of the transparency where the light is blocked from striking the emulsion will remain soft and can be washed away with water. The areas that are washed out of the screen allow the ink to pass through in the printing process.

Transparencies

1. Photo copy Transparency

A drawing or collage can be photo copied onto transparent photo copy paper. Turn the darkness setting to a fairly high level on the copy machine so the dark areas in the transparency are dense enough to block the UV light. The tansparency should be a positive one.

2. PMT Transparency

Any drawing, collage, or photograph can have a transparency made from it using the PMT camera. (See PMT camera directions)

3. Computer Transparency

An image can be scanned into Adobe Photoshop, manipulated and printed on a transparency.

Scoop Coating the Emulsion in the Screen

1. Mix the sensitizer with the emulsion as directed on the bottle.

2. Pour the emulsion into the Scoop coater.

3. Remove the screen frame from the base board.

4. Hold the Screen vertical on a table top and place the scoop coater edge at the bottom of the screen. Tip the scoop coater until the emulsion is on the screen and the pro-angle is parallel to the mesh. Pull the scoop coater up to the top of the screen with uniform pressure and speed. As you pull the scoop coater up a thin layer of emulsion will be applied to the screen.

5. Place the screen in the dark room behind the black plastic until it is dry or blow dry it in the dark room.

6. Clean up the emulsion and scoop coater with water.

Exposing the Emulsion

1. Work in the dark room to prepare the screen for exposure. Place the positive transparency on the screen exactly where you want it and tape it in place with clear tape. Be sure the ink or toner side of the transparency is against the screen.

2. Lay the screen and transparency face down on the glass of the A&M exposure unit. Place the cord in the unit so that it passes from the glass over the frame onto the screen and back out to the glass. Close the lid and latch it.

3. Turn on the power, blower, and vacuum. Set the exposure time to 1.00 and press the start switch.

 Wash Out the Emulsion

1. When the exposure is finished turn off the vacuum and release the pressure by pushing the vacuum release plug to the side. The plug is under the vacuum mat on the lower right hand corner of the unit.

2. Lift the lid and remove the screen.

3. Take the screen to the sink and spray water across it. The soft areas of the emulsion should begin to lift. Continue washing until all the soft areas are clean of emulsion and you can see through the screen in those areas.

4. Dry the screen using a blow dryer and fill any pin holes in the hard emulsion with screen filler.

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Printing

1. Cut the printing paper a similar size to the drawing, that is, the printing paper should be at least two inches larger in each dimension than your image size.

2. Make a stencil to protect the borders using mylar or butcher paper. Cut a window in the butcher paper the exact size of the drawing image. Tape it to the back of your screen so the boarders of the print will remain clean while printing.

3. Place the paper in the registration clips. Lower the screen and pour a bead of ink along the top of the screen.

4. Using even pressure pull the squeegee across the screen making sure that your fingers are spread along its length. Hold it at a forty five degree angle. The tendency is to hold the squeegee more and more vertical as it is pulled across the screen. Do not let that happen. Keep the squeegee at a 45 degree angle.

5. At the end of the printing stroke, scoop up the ink with the squeegee and place the ink and squeegee at the top of the screen.

6. Lift the screen and carefully remove the print.

7. Place another piece of paper in the registration clips and continue printing.

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Clean Up

1. When you are finished printing quickly clean the screen and squeegee with water and a brush. If you don't act quickly the ink will dry ruining your screen and the squeegee. Use a brush to make sure that all the ink is removed. Hold the screen up to the light to see if the pours of the screen are all open and allow the light through. If they are not continue cleaning until the whole screen is free of ink.

2. Also clean the table, sink, and anything else with ink on it.

Cleaning the screen filler off the screen

A. Wet the screen with water and rub a small amount of Wisk, Soft Scrub or ammonia and water into the screen using a brush. Never use ammonia and anything with bleach in it because together they create a deadly gas.

B. Let the screen sit for five or so minutes and scrub it again. Wash the screen with water and if necessary apply more Soft Scrub or ammonia and water and repeat the procedure.

C. When the screen filler has been softened, use the power washer to clean off the screen filler.

D. The screen is free of screen filler when you can see through the screen. Any area where you cannot see through still has screen filler in it. The screen filler does stain the screen but the stain will not interfere with future use of the screen.

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HOW TO THINK ABOUT A THREE COLOR SCREEN PRINT

1. To make a three color print it will be necessary to make three separate images on three separate screens. When printed on top of each other the three images must add up to a single image. Each color overlays the previous color and adds something to it. Work hard not to allow any of the colors to simply repeat what another color has accomplished. Gray, brown, and black will be the colors used in the first color print.

Brenda Zipfel

2. The first screen will be the one that prints the gray. It should establish the whites, the areas where there is no ink on the paper, the grays and create some detail. It should also cover the most area on the paper of any of the colors.

3. The second screen will be the one that prints brown. It should retain some whites, grays and establish the middle tones. It should create new detail and cover less of the surface than the gray.

4. The third screen will be printed black. It should retain some whites, some grays, some browns and establish the darkest detail. It should also cover the least amount of the surface.

5. In each screen both positive and negative texture is important for optical mixing of colors and for integrating them.

6. Avoid repeating what each color has already accomplished. Cause each color to contribute something new to the composition or modify what has already been done.

7. Negative marks and textures allow the color underneath to show through.

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