The tape can be black or colored electrical tape. The black electrical tape is the more common type of electrical tape and is used for insulation around the globe. Tapes of different colors are used for color coding. Taking a few examples, in the U.S., red tapes are used for low voltage, phase B; blue tapes for low voltage, phase C; brown tapes for high voltage, phase A; and orange tapes for high voltage, phase B. Others are yellow for high voltage, phase C; green for earth ground; and both grey and white for low or high voltage, neutral.
You should first determine the purpose for which you are buying the electrical tape. This is important because using the wrong color could lead to electrocution and other electrical problems. It is also important because some electrical tapes are only meant for indoor use while others are all-weather. Consider the specifications of the electrical tape you are buying. Consider such specs as the dielectric strength (the amount of electrical stress before breakdown), the percentage elongation, the operating/service temperature, the tensile strength and the thickness. If you are unsure of what type of tape you need it is advisable to ask a professional electrician.
3M Scotch, Nitto (Permacel) and JVCC are some of the leading brands of black & colored electrical tapes we carry. Some of their top products include 3M Scotch 35 Color Coding Vinyl Electrical Tape, Nitto/Permacel P-28 All-Weather Colored Electrical Tape and JVCC EL7566-AW Premium Grade Electrical Tape. A good tape is one that is UL/CSA listed. FindTape.com also offers black or colored electrical tape in bulk. To add a product to the shopping cart, simply click on a product image. To read more about the specifics of the product, hover over the product image and click the "Quick View" button.