● Imprint cotton shirts. As mentioned before, sublimation needs polyester in order to complete the process of transfer. Sublimation will turn out best with only 100% polyester shirts. Cotton shirts should be completed with heat transfer paper.
● Imprint 65/35 and 50/50 shirts with bright colors. Since a percentage of the shirt is still cotton, the sublimation ink does not have enough polyester to create a vivid transfer. The image will end up with dull colors, especially after washing. Again, using heat transfers for cotton shirts is really the best option.
● Imprint colored shirts. Any colored background drastically alters the imprint colors. Since sublimation will become part of the shirt, any color already on the garment will overwhelm the transferred image.
● Imprint non-polymer-coated items. Remember that sublimation is printing into the coating, not the item.
● Imprint gold/silver metal used by award companies. This is another instance where the background color of the substrate will interfere with the image.