: A straight zipper placed on a curved seam, such as the lower back, often creates a bulge because it doesn't follow the natural "S" curve of the spine.
: Shaping the center back seam of a pattern to match the body's curve rather than using a straight line. bulve.zip
: Industrial manufacturers often use a heat press to stabilize zipper length before it is sewn into high-precision garments. HOW TO REDUCE THE ZIP BULGE TUTORIAL | KIM DAVE : A straight zipper placed on a curved
: High heat from a dryer can cause the cotton tape around a zipper to shrink while the rest of the garment does not, leading to a puckered effect. Fixes and Prevention: HOW TO REDUCE THE ZIP BULGE TUTORIAL |
: Applying a strip of lightweight iron-on stabilizer or stay tape to the seam before sewing helps the fabric behave more like a woven material.