While the insulation materials that have been reviewed may be the most popular in the industry, they present several limitations when it comes to miniaturizing wire and cable components. The voltage rating of a given wire is a function of the specific material being used and the thickness of the insulation wall; therefore, UL and CSA have set standards for the wall thickness different materials may be to  meet different voltage ratings. These standards also address minimum tensile strength and elongation requirements. In order to obtain a 300V rating, PVC insulation thickness must be 10 mils or 16 mils thick. For a 600V rating, the thickness must be either 32 mils or 16/4 mils of PVC/Nylon. When trying to minimize the size of components, the use of PVC can be a significant roadblock. Generally speaking, XLPE and TPE insulations have thickness requirements similar to PVC.