There are tons of great benefits of working with sublimation and 100% polyester garments things like moisture wicking, durability, soft hand and beautiful bright vibrant colors are just a few of them. Unfortunately, there is also a little drawback which is those little transfer lines that can ruin a perfectly good sublimation shirt.
Fortunately, there are several steps that can be used to eliminate those transfer lines and typically some combination of the steps or using all of them combined will solve this issue. There is definitely a need to do some testing to see what method or methods will work best for you and your set up. There is no real magic button as there are several variables in this like the type of shirt, your heat press, the pressure and temperature used and other issues that could be causing the transfer lines.
The simplest way of overcoming this is to make the paper larger than the heat press this will illuminate the paper causing the lines. One thing to note, you can still have issues with the edge of the heat press causing lines, but this is normally due to having way too much pressure.
The next tip to try would be adjusting your pressure so that it is a light pressure but it still enough to give you a good transfer. You want your pressure to be medium for garment transfers with sublimation and that is between 40 to 50 psi (a four or five readout on most presses). One other tip is to thread the garment to give it less depth to get pressure lines.
The next way to reduce or eliminate the hard paper lines is to tear the edge of your sublimation transfer paper this will cause a more gradual edge and also a less pronounced line so I will not be as noticeable. This is more of a Band-Aid as the lines might still be there but could get you over the edge if you are close to solving the transfer lines issue.
The last trick to try is to use a special heat resistant foam to reduce or remove the edge line in your sublimation transfer. This is the most in-depth solution, but should give you the winning results. Here is a step by step guide:
- Take the heat resistant foam and cut it down to be smaller than your transfer paper, but larger than the image you are trying to transfer.
- Calibrate the press by putting the heat resistant foam in it and when the press closes, it should reduce the size of the foam by half its normal size.
- Place the foam on the location where the image is going to be pressed and then cover the entire platen with a Teflon cover sheet.
- Place the garment on the press in a threaded fashion and align the image area over the top of the foam piece.
- Use a light spray tack adhesive and spray your transfer and then put it over the top of the foam piece so the edges of the transfer are out over the edges of the foam.
- Place a blowout sheet over the top of the transfer and press according to the manufacturer instructions. Typically around 400 degrees for 45 to 60 seconds.
One other tip I can offer is to turn your garment inside out and thread it back onto your heat press and give it a 5 to 10-second press again this could potentially press out some of the lines but will not get rid of it completely. Also, see the tip of rubbing it against the underside of your press as shown in the above video.
Last note is to remember the not just the paper can ruin your shirt. Things like collars and buttons can also cause similar edge effects that will not be able to be removed. Always thread or somehow situate a jig to eliminate extra pressure from buttons and collars. The same tricks are also good for doing other types of transfers like heat transfer vinyl or heat transfer paper when you are pressing onto polyester garments.