Want to print on coraplast

Can someone tell me the secrets to printing on Coraplast. I have the press to hold it down, I bought the right ink and thinner. But I can't get it to come out right. It forms cobweb type stuff on it. What am I doing wrong?

Location: 
United States

This is not you problem but i wondered what kind of press do you have and do you use a vacuum pallet?