Hmm... it doesn't look like 100% cotton to me.It is a 100% cotton shirt
I will test that to see thank you for the idea.Hmm... it doesn't look like 100% cotton to me.
What brand t-shirt is it, and what transfer paper are you using?
You can test the shirt fabric by using a hot iron set to cotton temperature.
If it's 100% cotton the iron will slide easy over the fabric. If it feels sticky, then it has polyester content.