Sisal floor-coverings have been growing in popularity in recent years. Sisal is a natural fiber derived from plant leaves, and ranges in tone from light brown to ivory/gold, and is sometimes dyed or paint-decorated. It's tightly woven in rugs, and that weave tends to trap dry soil, so sisal needs to be vacuumed frequently. The nature of the weave tends to make the rug shrink and distort when cleaned with water-based cleaning systems. Alternative cleaning methods include "dry" foam cleaning, bonnet cleaning, dry solvent cleaning, or dry powder (such as "Host" or "Capture"). Often, sisal is blended with other types of fibers, such as wool. Backings vary, and some of them are susceptible to damage from dry solvents. Additionally, sisal fibers can "bleed" natural colorants very easily - this can be problematic, particularly when there's been a spill, and staining has occurred. Sisal rugs installed wall-to-wall can usually be cleaned without fear of shrinkage, but in every situation, care must be taken in order to avoid problems.