A thermoplastic polymer monofilament oriented from 3.0-6.0 times its original length having a diameter of 125-600 microns and containing 0.2-5.0% by weight, based on the weight of the monofilament, of glitter particles or film particles having a particle size of 50-400 microns in its longest diameter, a thickness of 2-50 microns and having a diameter to thickness ratio of at least 2 to 1 and wherein the longest diameter of the particle is not greater than 80% of the diameter of the monofilament and that provide the monofilament with an attractive appearance. A core sheath monofilament is also part of this invention wherein the core is a thermoplastic polymer monofilament having a sheath of the same or different thermoplastic polymer containing the above described particles. These monofilaments are particularly useful in toothbrushes and cosmetic brushes.