Variations in the materials and heat presses
Due to fluctuations in substrates and heat presses, the recommended parameters for the heat press may vary depending on your environment. In this regard, the recommendations for time, temperature, and pressure provide useful guidelines.
For optimal results, test different combinations of time and temperature to find the one that works best for your substrate and heat press setup. Remember that significant variations in settings can result in poor image quality. Also, note the times, temperatures, and pressures that work best for different products; this will allow you to refer to them when starting production.
Calibrating your heat press is recommended to ensure accurate temperature readings. For this procedure, temperature test strips are more accurate than using an infrared thermometer. SEC Associates has published a helpful video on YouTube demonstrating various methods for verifying the temperature accuracy of a heat press. Contact your heat press manufacturer or dealer for specific calibration instructions.
Recommended paper and media
Always use the paper and media recommended for sublimation transfers; variations in paper and media quality result in variations in printing, transfer, and finished product quality.
Overflow and margins
Print your images with a 6 mm bleed beyond the size of the material you are transferring. This allows for some error when aligning your items under the heat press.
Avoid burns
Higher temperatures generally require a reduction in processing time to prevent burning. This occurs when the substrate and transfer paper become too hot for too long, resulting in browning of the paper, a blurry image, incomplete transfer, and other similar problems.
Avoid faded images
Insufficient drying time and temperature can prevent sublimation inks from fully transferring to the substrate, resulting in a faded appearance. To achieve a more complete transfer, try increasing the temperature and/or drying time. Increasing the pressure may also be necessary, especially if the image is faded only in certain areas of the substrate and not across the entire surface.
Cool the sublimated objects
After transferring the image onto the surface, quickly remove the transfer paper. Do not stack the transferred objects on top of other items until they have completely cooled. Any paper residue remaining on the surface after the transfer can be removed with isopropanol.
Use software templates
Software templates are very useful for media you'll create repeatedly, such as tiles and mouse pads. Generally, you can download templates from the retailer where you purchased the media or from the media manufacturer.
Included with every Virtuoso system, CreativeStudio offers ready-to-use templates for most available products; new templates are added monthly.
Manage humidity
Introducing moisture into the sublimation process can produce undesirable results. During production with a heat press operating at 204°C, moisture can turn to vapor, causing the ink to evaporate, literally, without reaching its intended target. Some problems attributed to moisture include color shift (less accurate colors), bleeding, and uneven transfer of solid areas during printing.
Under normal conditions, a small amount of moisture may accumulate on the transfer paper; this is usually absorbed directly by the substrate during pressing. However, hard substrates such as metal and ceramics cannot absorb excess moisture. Therefore, it is important to take precautions to minimize moisture introduction during the process.
The first step is to prevent the paper from absorbing moisture. As a preventative measure, store your paper in a dry place. You can use a sealed container, such as a resealable bag. If you suspect the paper is damp, place it on the heat press for a few seconds. Don't press it; simply expose it to the heat. The heat from the press should evaporate most of the moisture.
Another tip is to use newspaper or food-grade paper instead of a Teflon sheet. The paper will help absorb moisture from the transfer sheet during pressing, which Teflon won't do. Be sure to use a fresh sheet of paper for each pressing cycle.
If you're working with clothing or textiles, it's also possible the surface contains some moisture. Pre-pressing the garment for about ten seconds should remove the moisture, as well as any creases. To avoid this problem, store your paper or textiles in a dry place. If you suspect the surfaces contain moisture, try these techniques:
- Place the paper on the raised lower base of the press and let it dry under the heated platen. Do not close the platen!
- Pre-press the textiles for ten seconds before transferring.
- Use a new, unstructured paper towel behind the transfer sheet.
Manage ambient humidity
You shouldn't just pay attention to humidity during pressing; you should also focus on your work environment. Generally, high humidity levels contribute to moisture problems. A dehumidifier can help eliminate these issues; however, reducing the humidity too drastically can negatively affect the inks and your equipment.
It is advisable to invest in a hygrometer and take readings. The ideal operating conditions for sublimation are 15 to 25 °C, with a relative humidity of 35% (without condensation).
Keep your press clean
It is important to protect the rubber stamp attached to the lower section of the heat press. The same applies to the rubber stamp in a mug press. Covering the stamp with a protective sheet of paper, a paper towel, or a Teflon sheet will prevent it from absorbing the sublimation ink.
- If you use paper: choose inexpensive white kraft paper, or a roll of white paper (cut to size), and discard it after each pressing. Unprinted newspaper is also a good option.
- If you use a paper towel: choose a white, unstructured towel from a cheap brand (the texture will leave a mark on the surface), and throw it away after each press.
- If you are using a brown Teflon sheet: clean it with alcohol after each use.
Avoid ghost images
Sublimation printing requires a tight connection between the transfer paper and the blank product under heat. For best results, you must ensure the paper doesn't shift as the ink is vaporized and dyes the product. If the transfer paper moves during the sublimation process, this can result in a blurry or ghost image—the latter creating a shadowy effect.
To prevent this problem, always attach the transfer paper to the product itself using heat-resistant tape or repositionable (temporary) spray adhesives.
Hard supports
When decorating hard surfaces, use heat-resistant tape to secure the transfer sheet to the product. Do not apply tape over the image area, as this may negatively affect its quality. Press the product down normally, then carefully remove the transfer. You can purchase heat-resistant tape from your distributor.
Flexible supports
One of the most common difficulties when working with flexible substrates is the transfer of dust, lint, or other airborne fibers to the textile during the pressing process. These impurities leave small blue marks on the fabric, which can affect the quality of your print.
The best way to avoid this problem is to use a sticky lint roller before each pressing. A simple adhesive roller from the corner store will remove almost all the particles you can see with the naked eye—as well as many others you can't see. It's recommended to get into the habit of running a lint roller over the fabrics before applying the transfer paper.
When using spray adhesive, spray the image side of the transfer paper from about 30 cm away. Do not spray the product itself! Then simply press the transfer paper onto the product. If you position it incorrectly, you can remove and reposition it. It is difficult to apply adhesive tape to flexible materials, such as t-shirts and mouse pads. Instead of tape, you can use spray adhesive to secure the transfer paper to the product.
Squeeze the product as usual, then remove the transfer. Ask your retailer for suitable adhesive sprays.
