Sublimation Transfers are dye not ink and meant for polyester not cotton. The dye does not embed into cotton and will wash out. The higher the polyester % in your finished product the more vivid/dark/true to color the image with dye into/on your product blank. We press our sublimation transfers at 400 degrees for 60 seconds. Remember, heat presses vary and you will find the "sweet spot" for time and temp for your individual press.
Sublimation is HEAT not Pressure, whereas screen prints and vinyl are all about pressure. We recommend you: #1) place a sheet of parchment paper between the front and back of tshirts (on the inside) where the sublimation transfer will dye to prevent the dye from going through the front to the back of tshirt (or front of tshirt if you are wanting the design on the back of the tshirt) or item you are pressing) . #2 place your sublimation transfer with design toward item you are pressing and use sublimation heat tape to prevent image from moving around which will cause "ghosting", #3) place a sheet of parchment paper larger than the top of your press over the sublimation transfer and area of item press will touch so as not to scorch your item being pressed, #4 place a $1 bill or whatever denomination half under press top but ontop of the last piece of parchment paper (the large piece). If you can pull the bill out of the press without having to pull hard you have the correct or preferred pressure. Too much pressure and the outline of your sublimation transfer will show when you press your item.
We also recommend you watch some youtube videos on how to sublimate whatever item you are pressing. We are not responsible for user error and hopefully our method helps you :-)