... side9)Top Sewing: top hemmed, or top heat cut, or zigzag, with string.10)Bottom sewing: double folded single stitch, or ... bag, back-seam bag, side gusset bag, perforated bag, color printing bag, sand bag, building material bag, chemical industry bag, transparent bag, antiskid bag, valve bag, sandwich bag, inner laminated bag, plastic bag, antistatic bag ...