Fusible interfacing tape / seam tape

Fusible interfacing tape or seam tape (in German often Vlieseline-Band or Bügelband) is a narrow tape material — typically 8 to 20 mm wide — used as an insert in seams, at necklines, shoulder lines, zip edges or waistband transitions. The tape is mostly made of non-woven fabric or a narrow twill and carries a heat-reactive adhesive on one side that bonds to the base fabric when ironed (fusing temperature usually 130–160 °C).

Function: seam tapes prevent sensitive edges from stretching (e.g. jersey necklines), seams from tearing (stress points in workwear trousers) or zips from “walking”. They also stabilise hem and facing folds. In outdoor manufacturing an additional waterproof seam tape is often welded over the seam to seal the needle holes in coated or membrane fabrics — this is called seam sealing tape.

• Build-up: non-woven or twill tape plus hot-melt adhesive
• Typical width 8–20 mm
• Use: seam reinforcement, edge stabilisation, hem formation
• Outdoor special form: waterproof seam sealing tape