A few weeks ago, a generous & well-meaning person bought me a rather large supply of generic unbleached #4 cone coffee filters. Not sure what they do exactly to make them so much more prone to backing up than the ones I normally use, but I think I've decided to give up on them, maybe keep them on hand for emergencies, think it's unlikely I'm ever going to get around to having 200 such emergencies, unfortunately. Dislike waste. Suppose the real waste was in making filters that don't work properly in the first place, the bastards.