Tacking thread, as the name indicates, is used for tacking together different pieces of fabric before sewing them together definitively. Traditionally, the colour of the tacking thread is in stark contrast to the colour of the fabric, making it easy to see and remove.

What is the point of basting sewing?

Basting stitches are intended to temporarily join fabric for several reasons. For instance, basting garment seams allows you to test the fit or a specific placement (such as for darts) before sewing more permanent stitches. Basting also can hold slippery fabrics together while you sew the regular stitches.

What type of stitch is tacking?

Uses. Tacking is used in a variety of ways; one of the most common uses is to easily hold a seam or trim in place until it can be permanently sewn, usually with a long running stitch made by hand or machine. This is called a 'tacking stitch' or 'basting stitch'.