Screen Printing Hamilton Ngo
Screen Printing – Hamilton Ngo
Table of contents Screen Printing …………………………………………………………...……….2 Safety Glasses ……………………….…………….………………………………3 Design ……………………………………………………………………………...4 Vector Graphics………………………………………………………….…..4 Rasterasion…………………………………………………………………..5 Designing……………………………………………………………………7 Color Separation …………………………………………………………….8 Screen Printing Pt. 1 – Film ………………………………………………..…..…..9 Screen Printing Pt. 2 – Screens ……………………………………………..…….11 Exposing Your Screen ………………………………………………..……11 Cleaning Out your Screen after Exposing …………………………………14 Taping …………………………………………………………….………..15 Blue Tape ….................................................................................................16 Screen Printing Pt. 3 – Printing …………………………………………..………17 Things to Keep In Mind When Printing …………………………………...19 Clean Up ………………………………………………………………………….20
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Screen Printing – Hamilton Ngo
Screen Printing Screen printing; (noun) The silkscreen printing technique; serigraphy http://dictionary.reference.com/browse/Screen+printing
“Screen printing is a printing technique that uses a woven mesh to support an ink-blocking stencil.” http://en.wikipedia.org/wiki/Screen_printing
“Screen printing or silk screening is a printing technique particularly suited for flat or relatively flat surfaces... Screen printing is most commonly used for t-shirts, garments and other fabrics… also used on all sorts of other substrate ranging from plastic to metal.” L.S. Wynn – Writing/Editor of wisegeek.org – Conjecture Corporation
“Screen printing is printing, using screens.” Hamilton Ngo
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Screen Printing – Hamilton Ngo
Safety Glasses It is required to wear safety glasses whenever you are present in the printing room, for your safety.
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Screen Printing – Hamilton Ngo
Design Vector Graphics Vector images are created using geometrical primitives such as lines, points, and shapes. Using Adobe Illustrator, you can create vector graphics, or recreate images as vector graphics, using the very simple, easy to use pen tool. With the pen tool, you can create anchor points in Illustrator. Every anchor point you create would connect to the previous anchor point, and will continue to do that until the last anchor point meets with an existing one. From the anchor points, you can use the ‘Convert Anchor Point Tool’ to curve each line that is created between each point to help you develop or recreate an image. The cartoon characters you see on your favorite show South Park can all easily be created, or traced and recreated, with the pen tool from Illustrator. The image on the left shows a shape being created with the pen tool. After converting anchor points to mimic the image’s boundaries, the vectored shapes were then filled with appropriate colors to
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Screen Printing – Hamilton Ngo
create a vectored image. The different vectored shapes in the image on the left helps make up the head, nose, mouth, and other figures of the Bape logo.
Rasterisation Rasterisation (or rasterization) is the task of taking an image described in a vector graphics format (shapes) and converting it into a raster image (pixels or dots) for output on a video display or printer, or for storage in a bitmap file format. (http://en.wikipedia.org/wiki/Rasterisation). In English, rasterizing an image basically means to make an image bigger, without it being pixilated, or looking like poo. When working with Adobe Illustrator, the pen tool allows you to rasterize an image. Making an already existing image larger will always increase the size of the existing pixels as well. Rasterizing is effective in making an image more visually appealing. On the right side of this page, you can see two twitter bird logos put behind texts. One logo is much larger than the other, but is also fuzzy looking. The fuzzy look comes from the enlarged pixels from the existing, smaller, twitter bird logo. Both logos are both the same exact image file. But at the same time, they are different in size.
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Screen Printing – Hamilton Ngo
Below are two images of the Protoss logo from Starcraft 2. Visually, you can determine that the image on the left has fuzzy edges compared to the image on the right, but they are the same size. That is because the image on the left was increased in size and the image on the right was a vectored replica of the original, increased image. The original image was enlarged to the user’s preferred sized, then simply traced with pen tool, then filled with black in Illustrator, making it seem smoother and more visually appealing. This is a good example of how rasterizing an image can be effective.
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Designing To design: 1) Open Adobe Illustrator 2) Find an image you would like to design and print. Save it somewhere on your computer and place it in Illustrator (file > place). 3) Once the image is placed, recreate the image with pen tool by creating anchor points around the image and use the ‘Convert Anchor Point Tool’ to help form the image. It is recommended to do this with your fill off, to only see your anchor points and lines. a. If the image is just one figure, with one color, you only need to create one vectored image. b. If the image has multiple colors, you will need to create multiple vectored images of each section of your image, if you plan on printing those colors on something. c. If there is unwanted space inside the image you want to print, you will still need to create a vector image, to help separate that from the actual image you are printing. 4) Once you create your vectored images, fill the vector shapes with appropriate colors to complete your design. 5) Make any necessary changes to meet your preference of the design.
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Color Separation Color separation is important. In the image above is a completed design, in multiple colors. When printing, you will be handing a screen to print on for every color that is included in your design, if that is what you want. For this design, we would have to create three screens. Creating one screen with everything shown above would print only one color onto your design.
Separating colors will allow you to print different colors, not just one, for an entire image. Remember that color separation is not required if you have only one color. But it may be required if you have empty space in your image that you do not want to print on.
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Screen Printing – Hamilton Ngo
Screen Printing Pt. 1 – Film 1) Create a design on Adobe Illustrator. 2) After creating a design, you may print it on film paper. a. Print only black ink on film. b. Separate each color. Each color should have its own film. c. To print on film in Illustrator (in Mr. Bowers’ room): i. Make registration marks if you are working with two or more screens. It is not required, but they do help. Registration marks is like a target with a plus sign going through a circle, on the very top and bottom of the design, parallel from each other. ii. File > Print iii. Setup (bottom left in pop up window) iv. Select the PlateMaker printer, then hit ‘preference’ v. Click the ‘Paper/Quality’ Tab, then change paper source to ‘Manual Feed’ vi. Change media to ‘Film’ then hit OK. vii. Click on print, but make sure the PlateMaker is still selected. viii. Change media size to TABLOID. ix. Click print once more in the last pop up box. x. IMMEDIATELY grab a sheet of film and manually feed it to the printer. xi. Repeat the process for each color you will need to create a screen for.
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d) Once your designs are printed onto film paper, run them through the conveyer drier. The conveyer drier is located in the printing room. When the film runs through the conveyer drier, the black on the film looks more ‘solid’ or ‘thick’. This step is important because it affects how well a screen may be exposed with your film paper.
Looking at the conveyer dryer from the view point shown in the image, you want the film to go in from the left side, and come out the right. Be sure to have the film lay down flat. You can do more than one at the same time as long as they are not on top of each other. ☼ WARNING – CONVEYER DRIER IS VERY HOT. USE AT RISK.☼
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Screen Printing – Hamilton Ngo
Screen Printing Pt. 2 – Screens After your film paper made it through the conveyer drier with your design on it (IN BLACK), you can begin making your screen(s) if your design was made the way you wanted it to be on film paper.
Fun fact: Screen printing screens are made out of silk and other material. If you look closely, screen printing screens are made up of hundreds of holes (making them screens), allowing ink to pass through.
Exposing Your Screen The first thing you do in working with screens to print on is exposing your image on the screen. Exposing your screening is a fairly simple process, if you follow these instructions correctly: 1) Grab a screen that is not being used, with newly placed emotion on it. Emotion is a chemical that is applied to screens to prevent ink from passing through. Additionally, it will help you create figures you want in your screen for screen printing. Emotion is usually orange. a. If you are working in the small room where the exposure machine is, be sure to keep the curtains closed. This prevents UV rays to come in, which may affect the emotion that is used on the screens. May only have up to three people at one time in that area.
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2) Tape your film paper with the design on your screen, on the back side (not the squeegee side). The film paper should be facing you, if you were looking at the squeegee side. Be sure to line the film paper up on the screen parallel to each side, using a ruler. a. Only two pieces of tape are needed (one on the top of the film and one on the bottom). b. Use one screen per film. 3) After taping your film paper to your screen(s), you may now expose the screen. a) Turn on the exposing machine by simply flipping the on/off switch to on. b) Put your screen in the machine by lifting up the top. Keep in mind that it does not stay up on its own, so you may need to keep it up yourself, which does not take a lot of work. c) The screen should be facing up with the squeegee side.
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Screen Printing – Hamilton Ngo
d) Around the platform that your screen rests on should be two cords. Be sure that your screen isn’t resting on top of the cords, but instead have the cords lay around the screen. e) Close the top, and secure it with the two notches that lock the top down. f) Hit start whenever you are ready, and wait for the machine to work its magic. The process should take several seconds, no more than a minute. It is important to keep your eyes on the machine, in case if anything wrong happens. a. The machine should work as a vacuum, sucking in the screen tight and hugging it with its rubber top. b. As the machine is doing that, it will expose the screen and film with bright lights. g) When the exposure process is done, lift up the notches that lock the top of the machine so that it unlocks it. You may then lift up the top and remove the screen. h) Continue these steps for every screen you will need to expose. a. 1 film design/color = 1 screen 4) Once you have your screen(s) exposed, remove the film paper from the screen and place them in an appropriate place. There should be a cabinet in the room for old used film paper.
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Screen Printing – Hamilton Ngo
Cleaning Out Your Screen after Exposing One you have exposed the design(s) you want on your screen(s), clean it out with water and force. There should be a spraying machine in the printing room that shoots out water at a high speed. Follow these instructions to clean out your screen: 1) Set your screen in the platform of where it is appropriate to spray water, squeegee side facing out. You may spray two screens at one time. 2) Using the spray machine-like thing, spray the screen(s) enough to see the design or image on your screen. Do not spray too close to the screen. Spraying too close with a lot of power may push off emotion from unwanted areas, which is bad. 3) Once you can barely see your image, flip the screens so that the squeegee side is facing away from you. 4) Spray all around so that the emotion in the areas of your image comes off. This step takes some time.
Your screen should have no emotion in the areas of the image in your screen. To the left is an example of a screen that had been exposed and cleaned out. The emotion of where the image was placed came off, forming the image on the screen. This is why exposing is so important in creating your screen(s) for screen printing.
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Screen Printing – Hamilton Ngo
Taping When cleaning out your screen(s), you may accidentally spray off some emotion in unwanted spots where you would want emotion to stay. It isn’t a big issue if you do. You would probably have to start exposing process again for a screen if you sprayed off emotion that connected to the actual image, or if you sprayed a lot of emotion off from the actual screen.
If you have a small spot of emotion missing, you could easily tape it off so that ink does not go through that part of the screen when printing. Do not tape while your screen is wet.
This image shows tape being used to cover up a spot that unwelcomed ink. For more detail, the image shows tape used to cover up a registration mark. When working with registration marks, you do want to print on them to make sure your design is lined up with other registration marks on other screens. But when actually printing on a final product, you would cover the registration
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Screen Printing – Hamilton Ngo
marks to block any ink from being pushed through. Nobody wants a random registration mark on their tee shirt. To properly tape a screen: 1) Find spots on your screen where there is no emotion that you do not want to print on. 2) Apply tape over that layer, from the back side of the screen (not the squeegee side).
Blue Tape When looking at the screens, you can see that not every single part of the screen is covered in emotion. This space that is not covered in emotion actually hugs around the emotional surface, which is hugged by the frame of the screen. When printing larger images, it is important to tape around the area that you will be printing around so ink does not pass through these unapplied areas.
To cover up these areas, grab the special blue tape provided. Apply the tape along the outer frame of the screen, as close as you can to the corners/edges. You do not need to cover the entire perimeter of the screen’s inner frame, but apply tape where it may be close to making contact with ink. When working with this kind of tape, do not rip it by hand. It will be difficult, and tape may be wasted. Instead, simply use scissors and cut the tape, for as much as you may need.
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Screen Printing – Hamilton Ngo
Screen Printing Pt. 3 – Printing Once you have successfully taped up spots on your screen that may be missing some emotion, you are now officially ready to print ink on whatever it is you want to print on.
The first thing to do is to find an appropriate printing press that you would like to work on. In the printing room, there are two printing presses. One press supports up to six screens, while another only supports up to four. Choose wisely- base your decision upon how many screens you will be working with.
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Once you have chosen an appropriate printing press, you may then start printing. 1) Place your screen on the printing press. Line up your screen to your preference. There should be things such as lines to help guide you when lining up your screen on the printing press. 2) Once your screen is lined up, grab an article of clothing and allow it to hug around the printing press’ pallet. Have the side that you want to print on, up towards you, and outside of the article of clothing – not inside the shirt. Use sticky spray to assist you if needed (apply on pallet). 3) When you have completed step two, push the press down and visually see where your image will be printing. Is it where you want it? 4) When you are ready, apply ink to the screen from the bottom of the screen (side furthest from you). Ink does not need to be applied to the very bottom, but instead just below your registration marks or your image that is displayed on your screen. 5) Push the press down by a little bit, but not all the way down, and flood the ink. Flooding is when you take a squeegee, and move the ink towards you with a good amount of force. You should only flood with a single stroke. 6) After flooding, put the press all the way down and squeegee the ink upwards (away from you) TWO TIMES with a good amount of force. 7) Lift up the press to review your printing. 8) The ink on your article of clothing will be wet. To dry it, use the conveyer drier.
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Things to Keep In Mind When Printing: 1) When working with multiple colors, it may be easier to print all of your colors over white. Having one white coating underneath other colors may require less ink, work, and time from you. 2) Flash dry ink that is wet, if you still need to work on your printing on the same article of clothing. Simply apply the flash drier over the ink area for several seconds. You may need to flash dry something multiple times, depending on how well you print, etc.
3) When working with two or more colors, always line up your first screen you are printing on with the lines provided on the pallet. Then line up your future screens with that screen’s registrations marks. If your registration marks print over the already-applied-registration marks, then you can tell that your screen is lined up well with the previous screen.
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4) When running clothing through the conveyer drier, make sure it is lying completely flat as it can be. Lift the drier up if needed (for hoodies, etc). Nobody wants to burn their soon-to-be-grade-A shirt.
Clean Up Working with screens and ink will always be messy. It is important to clean out screens, squeegees, etc to allow others to continue printing new designs.
Here are the basics you may need to know when cleaning up screen printing utilities:
Gloves may be helpful when cleaning up screen printing materials. Ink is not very easy to get off compared to most substances.
Be sure to clean off the gloves before returning them.
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There are several ink cups with different colors. When being handled, ink may spread somewhere on the cups, sticks, press, etc. It is important to keep things ink-free. Minimizing the amount of loose ink in an area can prevent your favorite outfit from being ruined. The ink you see in the photo to the left is used in screen printing, when you print on clothing. When working with window cling designs, you may work with alcohol-based ink. Alcohol based ink is very runny, and dries up really fast. When working with it, you want to print as soon as you can, and clean up as soon as possible, to prevent ink from drying too quickly.
Other items that may be screen printed other than clothing and window-cling products may also be vinyl stickers.
When cleaning squeegees, it is important to get off all of the ink. You want to be able to get the ink off the blue AND wood surface. Make the squeegees clean enough so apply it to your bare skin without any ink getting on you.
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Use cards to remove mass amounts of ink and put the extra ink back into the original containers that they may have came from. Use paper towel to assist you in removing ink from squeegees, screens, etc.
To clean screens, use cards to remove any excess ink and return it back to its original container. Then use paper towel to wipe off as much ink as you can from the screen. You want to be able to only see emotion on a screen. Use appropriate chemicals to assist you. Be sure to remove as much ink as you can from the actual frames as well. When possible, also remove all tape from both sides of the screen and remove any ink around the taped areas.
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The image on the right shows multiple screens stacked after being cleaned out. To the right of the screens are a few screens added into a blue container that has chemicals that help remove ink and emotion from the screens. After cleaning out screens with paper towel, put three screens in that containers and allow them to sit for about 5 minutes. After, take out the screens and place them in the cube like structure shown on the left. You can clean two at one time.
The screens can then be sprayed until there is no more ink and emotion remaining. Sometimes, it may be harder to get off.
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Screen Printing – Hamilton Ngo
After the screens’ emotion and ink is removed, you may then degrease the screens. After degreasing, rinse the screen out once more and allow the screen to dry somewhere safe.
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