I would like it to close a little better when filling the cup, meaning when I put herbs inside and wet the paper a bit to close it, it shouldn't open so easily if I stir it or re-extract it. Other than that, the size is just fine for the amount of herbs I use (up to one and a half tablespoons of green or chamomile but even finely crushed mountain herbs). It withstands several extractions and doesn't leave a taste in the beverage.