Let’s take a moment to talk about why white 100% polyester T-shirts are best for sublimation. First and foremost, it's important to understand that the natural cotton fibers do not react to the sublimation dye when heat pressed. Polyester, on the other hand, is a synthetic fiber that works perfectly with the sublimation dye.
Here at HPN, we tried to sublimate onto a 100% cotton t-shirt. The initial result was very weak, with the image looking faded with very poor definition and bland, lifeless colors. It actually got worse after washing.
We also tested a 50/50 cotton-poly tee. It looked way better! The colors weren't as bold and vibrant as 100% polyester, but it got the job done. In fact, some people preferred this transfer because it has a cool “vintage” look to it. This shirt faded just a little bit more after a few washes, but not too much. This is because the cotton fibers in the blend did not fully react to the sublimation dye, and had the image wash out on that portion of the garment. A good rule of thumb is that the more cotton in your blend, the more fading you’ll get after washing.
If you have a colored 100% polyester tee, you can still sublimate it. However, the color of the tee will heavily affect the final look. For example, we tested the same image on a blue 100% polyester shirt. The darker parts of the transfer looked good, but the lighter parts got lost in the blue. Because sublimation printers don't have any white ink, any white portions of your graphic are left as a blank space on the page (to be filled in by the white color of your substrate). So where the graphic on our blue test shirt should have been white, it appears to be blue.
For all of our testing in this blog and accompanying video, we printed our sublimation transfers with a Sawgrass Virtuoso SG400 Sublimation Printer and pressed them with an HPN Signature Series 15"x15" Auto-Open Heat Press. For more information on sublimation, please visit us at HeatPressNation.com!