Silkscreen Printing: Diy T-Shirt Customization At Home

Screen printing your own T-shirts is a fun and inexpensive way to express your individual style. It's also a great way to transfer a printed design onto fabric. The technique involves a chemical process called photo emulsion, which might sound complicated, but is actually quite simple. Here's a step-by-step guide to get you started on creating your own unique T-shirts at home.

Choosing a design and printing it onto a transparency sheet

Choosing a design for your T-shirt is the first step in the screen-printing process. You can either design the artwork yourself or have a customer provide it for you. It is important to remember that the quality of the final print will depend on the quality of the original artwork.

When creating a design, it is best to opt for clean, simple designs with clear contrast between the foreground and background elements. Avoid intricate details, thin lines, and black-and-white photographs. Instead, go for a silhouette with one colour. You can use vector graphics or create designs in vector-based software, which are easily scalable without a loss in quality.

Once you have your design ready, you will need to print it onto a transparency sheet. This is a clear, transparent sheet or film with your design printed on it using an inkjet or laser printer. The transparency sheet will then be used to transfer the design onto the screen.

• Prepare your design: Use graphic design software like Adobe Photoshop, Illustrator, CorelDRAW, or Inkscape to create or finalise your design. Ensure your design is high-resolution (at least 300 DPI) and in the correct colour mode (CMYK for full-colour designs or Grayscale for single-colour designs). Adjust and refine your design as needed, ensuring that all elements are pure black (RGB 0,0,0 or Hex #000000).
• Set up your printer: You will need a printer capable of producing high-quality prints. Ensure it is in good working condition and has a manual feed option.
• Select the right transparency paper: Use transparent paper or film specifically designed for your printer type (inkjet or laser). This is crucial to ensure that the ink passes through the stencil well and produces a sharp image.
• Configure printer settings: Set your printer to the highest quality print mode. Select the appropriate paper type ("Transparency", "High-Quality Inkjet Transparency", "Specialty Paper", or "Gloss"). Disable any scaling or resizing options, and ensure your design is set to print at the expected size and placement.
• Print your design: Load the transparency film into your printer, making sure it will be printed on the rough/textured side. Print your design and allow it to dry completely before handling to prevent smudging.
• Inspect the transparency: Examine the printed transparency to ensure it accurately represents your intended design, free from any imperfections.

By following these steps, you will have successfully printed your design onto a transparency sheet, ready to be transferred onto your silkscreen for T-shirt printing.

Setting up your workstation and mixing emulsion and sensitizer

Setting up your workstation is the first step in silkscreening a T-shirt at home. You will need a clean, flat surface to work on, preferably in a dark room or closet with no windows, as emulsion is light-sensitive. Gather your materials: a screen, a squeegee, emulsion, ink, and a transparency (film) of the desired image. You can buy pre-made screens or make your own by stapling "110" polyester mesh to a square wood frame.

Now, let's mix the emulsion and sensitizer. Photo emulsion usually comes in two parts: one bottle of emulsion and one bottle of activator or sensitizer. For the Speedball diazo photo emulsion, fill the Diazo Sensitizer bottle 3/4 full with cold water, shake well, and then pour the contents into the Diazo Photo Emulsion container. Mix until the photo emulsion is a uniform colour. Ideally, this should be done in a dark room to minimise light exposure. You can store the leftover sensitized emulsion in a cool, dark place for up to four months.

Elevating and coating the silkscreen with emulsion

Elevating the Silkscreen

Firstly, ensure your silkscreen frame consists of a wood or aluminium frame stretched with polyester mesh. The mesh holds the image onto the screen and allows ink to pass through when pressed with a squeegee. Before applying the emulsion, clean the mesh with a special screen-printing degreaser to remove any dust, lint, or particles. This step ensures that no bumps or pinholes appear in your emulsion later on.

Coating the Silkscreen with Emulsion

• Prepare the Emulsion: Emulsion is light-sensitive, so the coating process is typically done in a darkroom with special light-safe yellow bulbs. Different types of emulsion have varying levels of sensitivity, shelf life, and ability to capture detail. Choose an emulsion that suits your darkroom setup. If using dual-cure emulsion, mix it with diazo to create a light-sensitive solution with an extended shelf life.
• Use a Scoop Coater: The most popular tool for coating a screen with emulsion is a scoop coater, which comes in various sizes. Choose a size that provides at least one inch of clearance between the scoop coater edges and the inside edges of the screen frame. Ensure the edges of the scoop coater are free from flaws, nicks, or damage, as these can damage the mesh of your screen.
• Fill the Scoop Coater: Fill the scoop coater only halfway with emulsion. Overfilling can lead to messiness and uneven coating. Distribute the emulsion evenly across the inside of the scoop coater.
• Coat the Screen: Place the screen in a standing position, using a screen-holding stand or rack, with the print side facing out. Hold the scoop coater with both hands, placing the sharp edge about an inch above the bottom of the inside screen frame. Roll the scoop coater forward until the emulsion touches the screen mesh all the way across. This step is called building a bead of emulsion on the mesh. Be careful not to roll too far forward to avoid spillage.
• Move Upwards and Rotate: Slowly move the scoop coater upwards, maintaining pressure to keep it in contact with the mesh. This ensures an even thickness of emulsion. When you reach an inch from the top edge, slowly rotate the scoop coater back and away from the mesh. This allows the emulsion to flow back into the scoop coater without dripping on the screen.
• Complete the Coating: After the emulsion has returned to the bottom of the scoop coater, continue moving upwards to cleanly shear the remaining emulsion from the screen. Repeat the same process on the opposite side of the screen (the ink side). One coat on each side is usually sufficient for manual screen printing.
• Dry and Store: Place the coated screens in a light-safe, dust-free darkroom to dry. Store them print-side down in a drying rack, allowing the emulsion to pull down and through the mesh, encapsulating it. A low-humidity room will speed up the drying process.

Exposing the emulsion to light

Now that you have your image cut out and your screen coated with emulsion, it's time to expose the emulsion to light. This will make the emulsion permanent and allow you to wash away the parts of the screen that were covered by your image. Here's how to do it:

• Place a light source above your work area. You can use a regular 150-watt incandescent lightbulb or a 20-watt LED bulb. The light source should be positioned approximately 18 inches above the screen.
• Cover the screen with a towel to prevent light from hitting it until you are ready to expose it.
• Place the screen on a black matte background with the "back" of the screen (the non-recessed part) facing up.
• Place your cut-out image onto the screen in reverse. Make sure you are holding the image so that you see it as you want it to appear on your t-shirt, then flip it over and place it on the screen.
• Place a clean piece of glass over the image to hold it tightly against the screen.
• Expose the screen to light for the required time. The exposure time will depend on the size of your screen and the type of emulsion you are using. Refer to the instructions on your emulsion package for the specific time and distance recommendations.
• After the allotted time, remove the glass and paper cut-out. You will see a faint image on the screen.
• Wash the screen with a high-pressure tap, such as a shower head or outdoor garden hose. Spray the screen with lukewarm water, focusing on the image area.
• Continue spraying until the image becomes more visible as the emulsion washes away.
• Allow the screen to air dry or use a fan to speed up the drying process.

Now that your screen is exposed and dried, you are ready to start printing your t-shirts!

Transferring the design onto the T-shirt

Now that your screen is ready, it's time to transfer the design onto your T-shirt.

Slip a piece of cardboard inside your T-shirt to prevent ink from reaching the back of the shirt. Position the flat side of the screen against the front of your T-shirt. Place the image in the upper centre portion of the shirt for a traditional look, or place it off-centre for a less conventional design. Just make sure that the fabric underneath the screen is not bunched or wrinkled; otherwise, the screen printing ink will leak out of the stencil.

Put 1 tablespoon (15 mL) of screen printing ink above your design. Arrange the ink so that it is a line that is the same width as your design. This will make it easier to pull the ink down evenly over the stencil.

Use a second, clean squeegee to pull the ink across your design. Pull the ink in a single direction to ensure that you create a smooth, thin layer. Continue to pull the ink over the design until it is evenly dispersed. For larger designs, add more ink if needed. Just be careful not to oversaturate your fabric with ink, as it might begin to bleed outside of the stencil.

Remove the screen from the T-shirt and allow the ink to dry before setting it. Lift the screen straight up from the T-shirt. Be careful not to jostle the fabric as you do this. Then, refer to the manufacturing instructions on your particular screen printing ink on how long to let the ink air-dry. Generally, the ink will take 30-60 minutes to dry.

Set the dried ink with heat to permanently press the design onto the T-shirt. Refer to the manufacturing instructions on the screen printing ink to see which method is best recommended to set the ink. Ironing is the most common method of setting screen printing ink. However, some brands may require you to expose the shirt to sunlight or set it in a dryer.

Frequently asked questions