Heat setting screen printing ink with an iron is an effective method to cure the ink, making it permanent and washable on fabric.
Understanding Heat Setting
Heat setting is a crucial step in screen printing that cures the ink, bonding it to the fabric fibers. This process ensures the ink becomes durable, washable, and resistant to cracking or fading over time. Without proper heat setting, the ink may wash out or degrade quickly.
Step-by-Step Guide to Heat Setting with an Iron
To successfully heat set your screen-printed fabric using a household iron, follow these steps:
1. Prepare Your Workspace and Garment
- Ensure Ink is Dry: Before heat setting, make sure your screen printing ink is completely dry to the touch. This typically takes 24-48 hours, depending on the ink type and humidity.
- Prepare Your Surface: Use a flat, heat-resistant surface, like an ironing board or a sturdy table covered with a towel.
- Pre-Press (Optional but Recommended): Briefly press the area to be heat set without steam to remove any wrinkles and moisture from the fabric.
2. Setting Your Iron Correctly
This is a critical step to ensure proper curing without scorching the fabric or the ink.
- Adjust Iron Temperature: According to the provided reference, "If it's a cotton shirt, set it on the cotton setting. For linen or wool, make sure you set the proper adjustment." This means you should set your iron's temperature dial to match the fabric composition of your garment.
- Cotton Garment: Set your iron to the "Cotton" setting.
- Linen Garment: Set your iron to the "Linen" setting.
- Wool Garment: Set your iron to the "Wool" setting.
- For synthetic blends or delicate fabrics, consult the ink manufacturer's recommendations or test on a scrap piece.
- Turn Off Steam: Ensure that the steam function on your iron is completely off and the water reservoir is empty. Steam can interfere with the curing process and potentially damage the ink.
3. The Heat Setting Process
- Protect Your Print: Place a non-stick barrier, such as a piece of parchment paper, a Teflon sheet, or even a thin cotton cloth (like a pillowcase), directly over your screen-printed design. This prevents the ink from sticking to the iron and protects the fabric from direct heat.
- Apply Heat and Pressure:
- Place the hot iron firmly and evenly over the protected design.
- Apply firm, consistent pressure.
- Move the iron slowly over the entire printed area. Avoid gliding the iron too quickly, as this won't allow enough heat to penetrate the ink.
- For most water-based screen printing inks, iron each section of the design for approximately 20-30 seconds. If your design is larger than your iron, move the iron to overlap sections, ensuring all areas receive adequate heat.
- Multiple Passes: Depending on the ink and fabric, you may need to repeat the process two or three times over the entire design to ensure thorough curing.
4. Cooling and Curing
- Allow to Cool: Once you've completed the heat setting process, remove the iron and the protective barrier. Lay the garment flat and allow it to cool completely before handling. The ink continues to cure as it cools.
Tips for Best Results and Longevity
- Test First: If possible, do a test heat set on a scrap piece of the same fabric with the same ink to ensure optimal temperature and duration.
- Avoid Scorching: Be mindful of the iron's temperature. If you notice any scorching or discoloration on the fabric or the protective barrier, reduce the heat.
- Read Ink Instructions: Always refer to the specific heat setting instructions provided by your screen printing ink manufacturer, as curing times and temperatures can vary.
- Wash After 24 Hours: For best results, wait at least 24 hours after heat setting before washing the garment. Wash inside out in cold water to extend the life of the print.
By following these steps, you can effectively heat set your screen printing ink with an iron, ensuring a durable and professional-looking finish.
