I too bought 5 packs. They are horrible. And.... I have a new cutting mat so that is not the problem either. I think they are just not that fine sharpened since they are to cut big thick carpet, not precise for fabric. I tried a couple of packages about 6 months or so ago and they seemed fine so I ordered more but these last ones are just useless. I will go to JoAnns and get the better ones even though they do cost more. But it will be less frustration and worth it.