Why is 100% cotton SAFER than 50/50 or Polyester fabric for printing Darks?
The 50/50 cotton/polyester blends have a problem called bleeding. The polyester fabric is dyed with a heated gas process that sublimates the fabric. When screen printers heat their inks to dry, the dye in the polyester fabric releases and actually dyes the ink on the shirt, shifting its original color. If you’ve ever seen white imprints on red t-shirts turn pink, it is likely a bleeding problem with polyester. Cotton is dyed is a solution and does not have this problem.