To obtain the subject base fabric with its constant load-extension rate in the warp direction within a specified range, low in residual shrinkage, high in dimensional stability, easy to process, and rich in touch feeling and stretchability, by using two-layer structural yarns subjected to real twist with polyurethane elastic yarn as core.
This base fabric for stretchable interlining is obtained by using two-layer structural yarns as warps or both warps and wefts. Each of the two- layer structural yarns is composed of polyurethane elastic yarn ≥60% in dry heat set rate as core and short fiber as sheath and lies subjected to such real twist as to be 2.5-7 in twist multiplier, and the polyurethane elastic yarn accounts for 5-20wt.% of the whole yarn. This base fabric is 8-20% in constant load-extension rate in the warp direction and ≥2% in residual shrinkage.