The Butt Seam, Lap Seam and Joining & Taping operations that we have discussed above were generally considered for use only in the basic knitted underwear categories.  But things have changed considerably in recent years.  Now these machines are used to sew a wide variety of products, from the basic underwear, to wetsuits, to fleece outerwear, to elastic braces, to fishing rod covers, to prosthesis covers -the list goes on and on.  It should be noted, however, that there are limitations as to how thick a material can be before these machines will not work. This limitation is related to the size of the stitch tongue on the throat plate.  The stitch tongue is made to only accommodate up to a size 090/036 needle (size 14). Anything larger and the stitch would not be formed properly and parts breakage may occur.  (Also, the largest needle size you can get from needle manufacturers is the 090/036.)