 On normal 22-count Hardanger fabric this is usually Pearl cotton #5, a heavier weight used for satin stitch Kloster blocks and motifs, and Pearl cotton #8, a thinner thread used for more delicate filling stitches and other surface details.On finer, higher count fabrics the combination of #8 and #12 threads is often more suitable.Hardanger embroidery uses satin stitch blocks known as Kloster blocks,
consisting of 5 parallel satin stitches, worked over a group of 4 x 4 ground threads.