Double lockstitch (Basic stitch type 301):
Advantages:
Ø Lower thread consumption than double chain stitch

Ø Same seam strength on the upper and lower sides
Ø Good seam strength owing to interlocking in the middle of the material (but not as strong as with the chain stitch)
Ø Easy tying of the seam end by reverse sewing
Ø No seam impressions on thin woven fabrics
Disadvantages:
Ø Considerable mechanical stress on the sewing thread when forming the stitch.
Ø Lower productivity owing to bobbin changing ( standstill and handling times)
Bartack :
Ø Double lock stitch for separate tying of the start and the end of seams
Ø Double lock stitch for tying belt loops, for example.
Ø Double lock stitch bar tacks for strengthening jeans pockets for example.
Double chain stitch (Basic stitch type 401):

Advantages:
Ø High seam stretching and high seam strength.
Ø Little mechanical stress on the sewing thread when forming the stitch
Ø The chain can safely run out without material – even at high sewing speeds
Ø Only marginal displacement puckering owing to interlocking of the needle thread and bobbin thread on the underside of the material being sewn.
Ø High productivity owing to large thread supply ( no spooling necessary)
Disadvantages:
Ø Twice the sewing thread consumption compared with double lockstitch
Ø Thick underside of seam-impressions possible on thin woven fabrics
Ø Seam opening in the event of skipped stitches.
Zig-Zag Stitch (Stitch types 304 and 404) :
Ø Exists as both double lockstitch and double chain stitch
Ø Primarily used in the corsetry sector
Ø Optimum stitch for decorative seams.
Overlock Stitch (Basic stitch type 501) :
Advantages :
Ø High seam stretching for edge trimming seams
Ø Excellent stretching properties
Ø Saving of working steps if a safety stitch type is used
Ø Needle thread determines the strength of the seam,while looper threads ensure good seam appearance and softness.
Ø Little mechanical stress on the sewing thread when forming the stitch
Ø High sewing speeds possible.
Ø High productivity thanks to large thread supply (no spooling necessary)
Disadvantages :
Ø Very high sewing thread consumption.
Flatlock Stitch (Basic stitch type 601 ) :
Advantages :
Ø High stretching properties
Ø Flat seams with no marks through the material on knitwear.
Ø Decorative seams if a textured thread is used.
Disadvantages:
Very high sewing thread consumption (example: 4 needle threads,4 looper threads, 1 face thread)