What is pinholing and what causes it?
Pinholing is a result of uneven ink coverage or poor ink flow. After the ink is transferred through the mesh onto the substrate, it should flow evenly and completely cover the image.

There are many causes of pinholing, which include:

• low surface tension levels
• contamination on substrate
• screen closed or contaminated
• age of substrate
• uneven application of topcoats or adhesives on pressure sensitive films
• inks not thoroughly mixed or not compatible with the substrate