Cap Solder - the end of the filter is dipped in molten solder, which fills the end opening. This is relatively inexpensive, but is limited to cylinders smaller than approximately 1/4" in diameter.
Fishtail Weld - the end is pinched together and welded. This is usually the least costly method and is used when the width of the end closure may exceed the outside diameter of the cylinder.
Flush Bottom - a wire cloth cup is attached to the filter with the bottom surface flush with the end of the cylinder.
Folded End - the end of the cylinder is folded and secured. Usually used with finer meshes and low to moderate volume.
Inverted Bottom - a wire cloth cup is attached to the end of the filter with the bottom surface recessed into the end of the cylinder. This method is usually less expensive than a flush bottom.
Running Crease - same as fishtail weld, except that the width of the end closure is confined.