Lint and/or broken filaments contaminate the fabric or heat press/calender by lying on the surface, which inhibits ink from gasing onto the fabric and causes a white spot.
Why does contamination occur?
Lint and/or broken filaments on the surface of fabric or heat press/calender blanket is a common occurrence, especially if heat press/ calenders are in close proximity to cutting, sewing, or finishing equipment.
Though rare, contamination can happen at mill stage.
The best practice for removing lint and debris is to take a compressed air hose and blow the lint from the heat press/calender and fabric prior to transfer.
CONTAMINATION IS A COMMON PROBLEM AND CAN BE SOLVED BY USING AN AIR COMPRESSOR.