Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Abstract: Results of an anthralin stain removal study on white 65% polyester/35% cotton, white 100% polyester, white 100% cotton, a white shower curtain, white tile with crevice, and white ceramic shower tile are reported. An optimum stain removal technic was developed by using a 10-minute soak in full-strength chlorine bleach (Good Measure or Clorox) followed by a water rinse and air drying. This technic completely removed all stains of 24-hour duration from the test fabrics. The stain removal test on shower curtains, floor tiles, and ceramic shower tiles was also discussed.
Anthralin