Did I Scorch My Shirt?
You have your transfers and apparel ready to go. You turn on your heat press, position the transfer on your red t-shirt, close the press, and lift up. The transfer applied easily and quickly but why is there a red box on my t-shirt?
Cotton Vs Polyester
The answer depends on the fabric. If your shirt is 100% cotton, and you used the temperature recommended on your instructions this is definitely moisture removal. If your shirt is at least 50% cotton like a 50/50 cotton/poly blend the answer is still moisture removal. The heat from the heat press has removed the moisture from the area it had contact with. As the moisture returns after application, the box will dissipate.
Before Laundered, press box seen
After Laundered, no scorch box, it’s gone as moisture returned
But if your shirt is 100% polyester it was most likely scorched. The best way to prevent scorching is to use the right product for the job. We all know Goof Proof, screen printed transfers is the fan favorite. But Goof Proof applies at 365 degrees, fine for cotton and most poly/cotton blends but too high of temperature for 100% polyester.
For polyester we recommend one of our low temperature transfers such as Elasti Prints. Elasti Prints applies at just 290 degrees. The lower heat will help reduce scorching.
Flexible Application Pads/Teflon Cover Sheets
What if I use a flexible application pad or a Teflon cover sheet to block the heat? This will block the heat and will reduce scorching but it also blocked the heat needed for the transfer to apply correctly. For this reason, we don’t recommend the use of either.
When In Doubt—test
If you are unsure if your polyester can withstand the heat. We recommend testing on the backside of one of the shirts. This way if it fails, the shirt won’t be ruined and you can explore other alternatives.