They self trim, do not smoke, do not flicker. I have tried every wick known to man and I like these the best. You should have gotten your samples by now. I would call them. They send a huge assortment for you to test with. I have bought 1000 at a time but it looks like you can get them somewhere else for 100. I think 1000 is about $36.00. Be persistant.....it is a really nice FREE sample.Dixie