Causes of staining do not include allowing the blood to dry, but using hot water when washing the pad will, as hot water sets protein stains (blood). Often, soaking pads for at least 4–6 hours (or overnight) in cold water with an oxygen bleach can assist in stain removal. Drying cloth pads in sunlight can help to fade stains. The fabrics used range from 100% natural fibres to 100% synthetics. Some commonly used fabrics include terrycloth, cotton, silk, hemp, and Gore-Tex. Specialty fabrics such as hemp, bamboo terry, bamboo velour, soy French terry, wool interlock and polyurethane laminate (PUL) may be used. PUL may be purchased from online nappy/diaper supply stores. Some styles of cloth menstrual pad have a waterproof layer to help prevent the pad leaking through while other styles of cloth pad may rely on more layers of absorbency and not include waterproofing. Wool can also be used as a natural, breathable backing that provides leak protection. Developing countries In developing countries, reusable or makeshift pads are still used to collect menstrual blood. People in these countries most often resort to either staying in their rooms during menstruation or using pieces of old cloth/ rags, old mattress foam and even infection-causing items such as leaves, husks, disposed cement bags, etc. Lack of access to feminine hygiene products affects women and adolescent girls around the world. This lack is directly tied to exploitation, school drop out rates, infection, early marriage and even child trafficking. Quality washable menstrual pads are now helping as worldwide awareness is growing - also evidenced by the global initiative of Menstrual Hygiene Day. Many NGOs are coordinating volunteers to sew effective washable pads with moisture barriers that, unlike disposables, can be used month after month. Effective management of menstruation is an under-recognized challenge for girls in low-income communities. A study in Uganda showed the effects of menstruation and education in communities of poor education, welfare, and health. Girls who received high-quality menstrual pads were less likely to miss school. The girls reported better concentration and participation due to not having to worry about staining their clothes. Studies have found that between 43% and 88% of girls and women wash and reuse cotton pads in India, rather than utilizing disposable pads. These numbers are particularly dominant in rural areas and low socioeconomic regions. The cotton pads are sometimes not sanitized properly due to washing with soap