Screen Printing Techniques

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YOU SHOULD KNOW HOW TO SCREEN PRINT. I AM GOING TO SHOW YOU HOW.




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GET A JOB

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G ET A JOB



“I’M LOSING DETAIL IN MY IMAGE AREA

“ All light will bend and thus an over-exposed stencil will result in the light bending around the edges of the details in the film positive. Thin lines will be decreased or be completely obliterated. Utilising the correct exposure time will lessen the loss. “



SCREEN PRINTING WHAT IS IT?

Screen printing is one of the early methods of printing. It involves the passing of ink or any other printing medium through a stretched mesh fabric on a frame that acts as a carrier for an image to be printed. Only one colour can be printed at a time. For multiple colours, multiples of screens will have to be made. One for each colour of the design, printed in registration with each other.

Registration is the means for getting multiple colours to match up when they are printed.


SCREEN PRINTING BRIEF HISTORY 1500 B.C to present day: The first sign of printing star ted with Fijians making stencils out of banana leaves by piercing tiny holes in the leaves, then pushing vegetable dye through the leaves. These images would be printed onto handmade bark cloth. 1907 Screen printing was first patented in England by Samuel Simon in 1907. It was originally used as a popular method to print expensive wall paper, printed on linen, silk, and other fine fabrics. Western screen printers developed reclusive, defensive and exclusionary business policies intended to keep secret their workshops’ knowledge and techniques. 1963 to 1968: Andy Warhol opens The Factory, which serves as a studio for his many ar t projects, including screen printing with his primary printer, Alex Heinrici, who is followed by Ruper t Smith.

1958 to 1975: Pop Ar t embraces processes of mechanical reproduction, setting the trend for duplicates and ready-mades. The focus turns to the end product, not necessarily the process used to make it.


DESIGN, ACETATE, DEGREASE, EMULSION, INK, 2 HOURS.


INFLUENCES ROY LITCHENSTEIN ANDY WARHOL Roy Lichtenstein used mass produced imagery taken from magazines, 1950’s comic books, adver tising and product packaging as the inspiration for his paintings. He enlarged images taken from comic strips and painstakingly imitated their Ben Day dots and primary colours used in cheap news printing. Roy Lichtenstein adopted industrial screen printing processes to create his paintings, blending the divide between commercial and fine ar t. With his bold accessible paintings, many of which parody the American culture of the time, Lichtenstein became one of the best loved American Pop ar tists of the twentieth century.

Andy Warhol star ted creating silk screen prints in 1962. He wrote that ‘with silkscreening you pick a photograph, blow it up, transfer it in glue onto silk, and then roll ink across it so the ink goes through the silk but not through the glue. That way you get the same image, slightly different each time. It was all so simple quick and chancy. I was thrilled with it. When Marilyn Monroe happened to die that month, I got the idea to make screens of her beautiful face, the first Marilyns’.



MESH WHAT MESH WILL I NEED? Mesh is ‘silk’ of the silkscreen. The fineness of the weave of the mesh determines the resolution of your print (LPI). The lower the number of LPI (lines per inch), the fewer holes there are, and rougher the edge of your print will be. The higher number, the finer the mesh is. This would be used for printing on paper, wheras a lower LPI such as 100 could be used to print T-shir ts. The holes are like pixels in a digital image. Mesh comes in three different colours Yellow, Orange and white. White mesh is fine untill you under take finer quality printing, then you will need a mesh that diffuses the light the least. This is what the orange mesh is used for to get very fine and precise images.

Silk

Screen


FRAMES WOOD OR ALUMINUM?

Mesh is stretched on frames made of either aluminium or wood. Aluminium frames are very light and never warp.

Wooden frames are nice and heavy and don’t move around when printing therefore you can print without any clamps. The downside with wooden frames is they can warp when heated.


SCREEN MAKING THE SCREEN I highly recommend buying prestretched screens because your screen tension will be perfect with these screens. It’s very impor tant that your screen is consistently stretched very taut, because if it isn’t, it will screw you up as it gradually moves and shifts on the frame. But it is possible to make your own frame out of wood from the hardware shop if you make the joints strong. You can also make a frame from stretcher bars and stretch mesh on it. If you do stretch your own mesh onto a frame be sure to use white tape on the back edges of the frame. The white tape keeps ink from getting into the crevices of the screen as you print and wash out, which helps keep the frame from getting soaked and warping during washout The faster the screen dries, the faster you can print again. A few different screens sizes are good to have around the print studio for different projects. Make sure the screens fit on your exposure unit and printing table.

WHAT YOU WILL NEED . Wooden frame . Screen mesh bigger that your frame by at least 3” . Staple gun with 10mm staples . Nylon twill tape, ideally 13mm wide . Scissors . Canvas stretcher (will help) . White screen tape (buy at screen-printing supply shops)


1. Collect the equipment you need before you attempt to stretch the screen. A wooden frame, screen mesh, nylon twill tape, scissors, a staple gun and staples.

6. Gradually work your way out from the middle of each side until the entire screen is stretched taut. Then cut off your extra mesh.

2. Lay the screen mesh flat on the wooden frame. The screen mesh should be bigger that the exterior dimensions of the frame by 3” on each side so you can pull it. Lay the twill tape along the frame, making a 90-degree fold at each corner. Allow approximately 2” of the twill tape beyond the edge of the frame before cutting it.

7. Use white screen tape to cover the whole wooden frame. Star t by covering the staples on the flat side of your screen.

3. Beginning in the middle of one of the long sides of your frame, staple every 10mm. Stretch the mesh as you go. Staple at alternating 45-degree angles through the twill tape and the mesh so the mesh doesn’t rip. 4. Staple about 5”, and then switch to the opposite side and do the same while stretching it towards you. It’s like stretching a canvas. Then staple 5” of the other two sides. 5. Go back to the long sides and secure 3” more on the left and right of what you stapled already, stretching the mesh down and out.


FILM MAKING A FILM POSITIVE Every opaque black mark you put on your film will print. You can use clear acetate to draw on with a paint marker or print using a house hold printer. If you’re designing your image on the computer you will need to print it out as black as possible without ink lines showing. To overcome this you can print on two pieces of acetate and overlay before you expose it.

If you want to print bigger than your A4 you can break your design down into several parts and tile them together.


You may find that printing out two transparencies and overlapping them will solve the problem of greyness. When printing onto to acetate from your computer design you need to make sure that the black is as dark as possible. The other alternative would be to use an established printers to get a solid black. This is also helpful if you want to print bigger than A4.

1.

Bitmap Resolution: 300 Halftone Frequency: 5 Angle 90 Degrees Shape: Round

2.

Bitmap Resolution: 300 Halftone Frequency: 20 Angle 90 Degrees Shape: Round

3.

Bitmap Resolution: 300 Diffusion dither

If your wanting to use photographs in your designs, then the best way and most common way would be to use halftones. A halftone image is made up of lots of dots varying in size and density.

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2.

3.



“JUST PRINTED ONTO ACETATE, THEN TOUCHED IT AND SPOILT IT BY TOUCHING THE PRINT. IS THERE ANYTHING TO HELP? “

“ You must use the right kind of transparency film for your printer. If you are going to use ink jet you must buy acetate for ink jet. It has a rougher side where your ink will be absorbed. “


“ I HAVE BEEN TAUGHT AND I HAVE LEARNED BY DOING “



EMULSION COATING A SCREEN Before you coat the screen with emulsion you will first need to degrease the screen. To degrease the screen you can use any washing up liquid and rinse well after. 1. To coat the screen you will need the to poor about 10 tablespoons (A2 screen) of emulsion into the scoop coater. 2. Using the sharp edge of the scoop coater place against the screen till the emulsion hits the screen evenly. Then at a consistent pace pull the scoop coater up. The screen will need to be at a 45 degree angle. 3. Once your happy with the coating of emulsion you’ll then need to put the screen in a dark heated cupboard for at least 30 minutes. Problems . The emulsion needs to be really thin. Where it is thick on the screen, it will not screen through. . The screen shouldn’t touch anything between coating and drying.

When you hit the top of the screen tilt the coater towards you whilst still pulling upwards. This will stop the emulsion from dripping.


EXPOSING BURNING THE SCREEN HOW IT WORKS Your solid black positive film blocks out the light when the light is shinning on the screen. The light hardens the negative so it can’t be washed out. This allowing the positive par ts to be printed through. If your burning at home then the setup is fairly easy. All you have to do is harden the light sensitive emulsion with the light source you place above the screen. Expose the emulsion using a 500-watt light for about 20 - 25 minutes. (It’s all trail and error until you find the right set up. This could take a few goes). Once you have exposed the screen you will then need to wash the screen. You’ll need to wash out the par ts that didn’t get hardened using a jet washer. It may take a minute for the emulsion to soften enough to wash out.

Make sure you wash both sides of the screen

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ANDY WARHOL

“ SLIGHTLY DIFFERENT EACH TIME... SIMPLE QUICK AND CHANCY “



PRINTING ONE COLOUR So now you’re ready to print! 1. First of all you will need to mix your acrylic paint. Using a cup, pour enough paint into it. Then add a third of the amount of paint using the retarder. This will prolong the paint from drying. Make sure you stir for a least one minute. 2. Setting the screen up take a little time to get it right so you will need to take your time. It doesn’t matter as much when you’re doing one colour print, but it will be good practice. You set the screen up using the clamps and brown packing tape on the screen bed to get it aligned and secure.

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3. Once the screen is secure and you’re happy with the alignment, you are ready to print. Pour a line of paint along the bottom of the screen, this should be about 4cm thick. 4. Flooding the screen. To do this you will need to hold the screen at an angle of 45 degrees so the screen isn’t touching the screen bed. Flood the screen by pulling the paint towards you with a firm press on the screen. Tilt the squeegee at a 60 degree angle. 5. Making sure you have paper under your screen, place the screen flat and star ting from the top pull the squeegee towards you firmly again using the 60 degree angle. 6. Pull the screen up to reveal your print and let the print dry in the drying rack. 7. You will now need to remove the excess paint that is left on the screen and clean the screen thoroughly using the washer. This step is vital because you need to be quick so that the paint doesn’t dry and stick to your screen. Then the screen will be unusable.

Emulsion Paint Mesh Positive

Instead of holding the screen up while you flood it with paint, put the roll of tape under the screen frame to support it while you’re flooding.


PRINTING TWO OR MORE COLOURS

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G ET A JOB Emulsion Paint

Printing two or more colours is fine if you use crop marks and tape. Using tape (masking tape works best as its thicker) on the bottom right edge for a rough position, i then use the crop marks to get the print in line. It takes time to get it right and you will find your own way of getting you’re prints working. Please take your time with the alignment.

Mesh Positive



“USE BROWN TAPE TO PROP THE SCREEN UP WHILE YOU FLOOD IT “


“ LEARN THROUGH TRIAL AND ERROR, IT’S WHAT SCREEN PRINTING IS ALL ABOUT “


COLOUR QUICK PRINTING You have finished printing one colour and you have washed the paint off screen but you want to overlay quickly. Well instead of waiting for the screen to dry, get some tissue and whip the screen down and get it as dry as you can. Make sure the frame metal frame is dry before overlaying.

Before you overlay, you should do a few test prints on some scrap paper, this is to ensure that the screen is letting the paint through, but also to see if the screen is dry.


RECLAIM CLEANING SCREEN As your screen can be re-used over and over again with lots of different burns on it. You must unsure you clean your screen correctly so the screen isn’t damaged for the next burn. To do this you will have to use toxic chemicals to melt the emulsion off, and of course with a bit of elbow grease. 1. First of all you will need to wet your screen. 2. Using a brush apply the reclaimer onto both sides of the screen. Leave for 15 minutes for the magic to work. 3. After 15 minutes wash off the emulsion using the jet wash at full power. Hold the washer about 6 inches away from the screen, to insure you don’t damage the mesh on the screen.

Problems . You can see emulsion on the screen still and it won’t come off. Try a second lot of reclaimer and work it into the stains using a brush. Put the jet washer full blast and right on the stain until the emulsion gives up. . You can see faint outlines of old prints that have stained onto the screen, but you can see through the screen. This means your not cleaning your screen well enough between each print. Put the effor t in.



WORD OF MOUTH


Do some jobs for friends. do some jobs for free. these jobs, especially the ones in which you have a lot of creative freedom, are just the kind you need to build your por tfolio. Then you will have more concrete base of projects to show to potential clients. While you are building a professional por tfolio, you should keep a few things in mind. If you’re smar t about your work, you can use what you’ve already done to generate more work. . Document these projects well. Photograph the final prints in a clean, professional way that communicates the project in your style. . Make sure your client, even if it is your friend, is satisfied with the end product. You want your friends to think you do a good job so they spread the word. . Leave your business cards in the right hands. If you want to do concer t posters, send an informational packet to a concer t promoter or a concer t venue. Send packets out to brands you like. Be creative and think about unusual people who need you to screen print things for them.


EVALUATE There are many things that can be achieved with screen printing that can’t be done with other printing process. There is just something magical about screen print that you can’t achieve with digital prints. It’s the charm of the handmade. Digital prints can give the feeling that they are being churned out without a thought or care for where they end up, what they’re plastered on or how many are thrown around. Screen prints are special. Screen printing also has a lot of unique technical qualities that other types of printing do not share. You can get powerful, vibrant colours that radiate off and T-shir t or a poster. You can use print with all kinds of amazing inks you can’t use in other printing processes, including fluorescent, metallic paints. There are a lot of groups on the internet that are low budget screen printers that will talk about the best kind of beer to water ink down with. This huge network is dedicated on sharing tips, for example, building a jig for printing CDs. It’s all based on experience, and, chances are, you’ll soon be able to answer other peoples questions. This idea lends us into the same of the interesting things that are going on in printing right now, and ideas about the future of screen printing.


“ Screen prints are special. They demand more attention because they are handmade. Someone took the time to make that poster and hang it up on the telephone pole by your house, so you should look at it for a second. “


KEYWORDS ACETATE - A transparent or translucent plastic material that comes in sheets or on a roll and can be used as the clear par t of a film positive. EXPOSURE - The amount of time light must be applied to the photosensitive photo emulsion on the screen for it to harden;also called “shooting the screen” or “ burning the screen”. FILM POSITIVE - The ar twork used to block light from the par ts of the screen you want to print; most of the time it is a transparency with opaque black ink on it—sometimes just called the stencil, the acetate or the positive. FLASHING - Printing two layers of ink to make the colour more saturated (Used on overprinting text). FLOODING - Filling the screen with a layer of ink while it is raised off the substrate to keep ink from drying in the screen, done between each print. GHOST - The stain of previous prints in the screen mesh after reclaiming; not a scary ghost, usually not harmful to future printing. HALFTONE - A pattern made up of tiny dots that are bigger in darker areas of the print and smaller in others, used in printing to create gradation; you’ll see these dots if you look at a picture in the newspaper with a magnifying glass. INK RETARDER - A fluid added to the ink or paint to slow its drying, to prevent clogging of the screen; different retardants must be used for different ink and paints. MESH - Fabric stretched on the screen to suppor t the photo emulsion MONOPRINT - A print like no other, either printed with a temporary stencil or no stencil, or painted with ink in a unique way through the screen. PHOTO EMULSION - A photosensitive fluid applied to the screen that hardens when it comes into contact with light and becomes impermeable to ink and water. PINHOLE - A single hole or a group of holes in the screen mesh not filled with emulsion, appearing in the print as a dot in a place that shouldn’t be printing; these are filled with emulsion in a process called “pinholing”. RECLAIMER - A chemical that melts the emulsion out of the screen when no more prints are needed from the design in the screen, and a new image desired. REGISTRATION - The process of matching up positives and screens to each other when printing multiple colours. SCOOP COATER - A trough-like tool used to apply thin layers of emulsion to the screen in preparation for drying and exposing it with a design. SQUEEGEE - A tool with a metal or wooden handle that holds a rubber blade and is used to squish the ink through the open areas of the screen down onto whatever is being printed. JET WASHER - a motor-powered water sprayer used to clean the dir t off of concrete, and to blast the photo emulsion and paint off the screen.


REFERENCES Book: Print Liberation, The screen printing primer, page 17. Website: http://www.thefinear tcompany.co.uk/abstract/abstract-LW5.htm Photo: http://v9.lscache3.c.bigcache.googleapis.com/static.panoramio.com/photos/original/8732773.jpg Website: http://www.visual-ar ts-cork.com/printmaking/screen-printing.htm Photo: http://s3.amazonaws.com/files.posterous.com/annabelharrison/ConSUHXWvP62esLMx4oEkpETfDX5D58hjbPVhIaEn6P6F61dxc04yTD7zKna/1962_Andy_Warhol_Marilyn_Dipty.jpg?AW SAccessKeyId=AKIAJFZAE65UYRT34AOQ&Expires=1305038668&Signature=oeCyqsFUvdwEL%2Fu rxMKCqhOBZlw%3D Book: Print Liberation, The screen printing primer, page 46 - 47. Book: Print Liberation, The screen printing primer, page 138 -139. Website: http://forum.cardmakingandpapercraft.com/tm.asp?m=12853&mpage=1&key=&#12853 Website: http://www.t-shir tforums.com/screen-printing/t121822.html Website: http://en.wikibooks.org/wiki/Screen_Printing/Common_Problems Website: Print Liberation, The screen printing primer, page 120. Website: Print Liberation, The screen printing primer, page 124.

Fonts used: Body text: Petita Light, 9pt Petita Medium, 9pt Headings: Akzidenz Grotesk Light, 18pt Quotes: Quicksand Bold, 23pt

10 Days in the screen print room 60 hours, 28 screens, Over 100 washes, Probably about a litre of emulsion used, About 3 pints of paint and retarder, 70 floods, 60 hours of fun, All at the university expense, Thanks!

Thanks Steve Lannin for introducing me to screen printing and helping me out along the way! Susie Smith for the guidance.


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