There are a lot of great benefits of working with sublimation and 100% polyester garments. Things like moisture wicking, durability, soft hand, and bright, vibrant colors are just a few of them. Unfortunately, there is also a small drawback, which is those little transfer lines that can ruin a perfectly good sublimated shirt.
There is a need to do some testing to see what method or methods will work best for you and your setup. 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 cause the transfer lines.
Remember that 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.
Learn more about preventing transfer lines.