I apologize for my ignorance. I have some woolen clothes, including hats (12% wool) and jackets. They do not have linen mentioned in their composition, but is there a danger that they are made with linen threads? What should I do with these items?
Assuming you live near a religious Jewish community, there is usually someone who is trained to check for linen. Ask around for a shaatnez checker.
Btw, you mention threads, but there is also concern for padding and reinforcement. In any event, a trained shaatnez checker should be trained for that also.
You lost1970 should also study the last Perek of Tractate Kilayim. You can obtain the Yerushlami Gemoro on that Tractate in English, if you find English easier or more palatable than Yerushalmi Aramaic.