I read one article in one of my beauty magazines. It has a list of ingredients that clog pores. I already kind of assumed this because some products I use clog my pores and others don't.
So here are some ingredients from that list. Cocoa butter and linseed oil clog pores. So do "isopropyl isostereate" and "butyl sterate." I don't even know what the last two are, I can't even pronounce them. But I know I see them in ingredients lists all the time.
Surprisingly good old sunflower oil and olive oil don't clog pores!