The needle feed mechanism prevents uneven material feeding.
Slippery materials (Sportswear, rain wear)
Different materials (Waist lining sewing of
skirt and slacks)
Overlapping parts (Stitching of jeans)
Lengthy articles (Curtain, quilt cover)
Sewing requiring quality (Placket stitchingof polo shirt)
Materials difficult to feed (Coat etc. Quilting / fleece)