I just started screen printing 4 months ago. I'm kind of new to the industry. I started printing a job today for some Carhart high visibility,lined sweatshirts. They are 100% Polyester. The setup went perfect. The line up and loading are perfect, and the first 20 or so are damn near perfect but i hit a couple of them that just seem to not want to accept the ink. Im using a 156 count mesh with a medium squeegee and a union soft hand black. Now the first ones are great looking and I had no problem printing them,(2 pulls) but then I started hitting a couple shirts that were almost ink-proof. Can someone help explain this to me?. I stopped early today so i dont ruin anymore 40 dollar sweatshirts. lol