It is important to remove all forms of foreign matter and devitalized, dead, or contaminated tissue as part of the process of preparing beds of wounds. Clinicians use the term wound debridement to refer to the process by which necrotic and other materials are removed from wounds. Slough or necrotic materials are the terms used for all kinds of non-viable tissues found in wounds. Necrotic materials have a brownish or blacking color whereas slough is fibrinous yellow in color.