Pad stitches are a type of running stitch

Running stitch

The running stitch or straight stitch is the basic stitch in hand-sewing and embroidery, on which all other forms of sewing are based. The stitch is worked by passing the needle in and out of the fabric...

made by placing small stitches perpendicular to the line of stitching. Pad stitches secure two or more layers of fabric together and give the layers more firmness; smaller and denser stitches create more firmness. They may also be used to enforce an overall curvature of the layers.

Usage

Tailors pad stitch a jacket's lapel and undercollar to give them more firmness and to help them maintain their curvature. The line of stitching usually runs parallel the direction of the most important curve of the layers. For example, pad stitches in a suit's lapel run parallel to the lapel's roll line; pad stitches in the undercollar of a tailored jacket run parallel to the collar's back edge.