Anyone doing electrical work will find constant need for high-quality black electrical tape like the Electrical Marketplace premium-grade electrical tape. There's also always a need for several different colored rolls of electrical tape. Black tape is used for all standard wrapping needs. Tape of other colors are used for specific purposes in electrical work. Here is the general rule of thumb for the use of different colored tape in electrical work:

• Green Electrical Tape: Any wire that has green insulation (or has some other colored insulation but has green tape around it) is a ground wire. Green electrical tape designates Earth ground.
• White Electrical Tape: Any wire that has white electrical tape insulation is normally a neutral wire - the wire that brings the power back to the service panel after it has gone through the load. However, if the wire is a color other than white but is taped white, it should be considered a neutral wire. A typical example would be the service entrance conductor coming into the main service panel.
• Black and Red Electrical Tape: These are two typical colors of electrical tape that designate hot wires. But hot can also be blue, purple, or any other such color (except green).
• Other Colored Electrical Tape: Electrical tape colored anything other than green, white, black or red electrical tape is used to label and identify cables. For example: You have a multitude of cables coming into the panel from all over the house, how do you know which cable goes where? Use electrical tape to band each end. The purple tape on the cable bath receptacle box, as an example, is matched to the purple band on the cable in the main service panel.

You will be tempted to use the cheap tape found in grocery and hardware stores. DON’T DO IT! Such tape will not have the insulating capability of high-quality tape. Look for good tape that is effective between 0 degrees Fahrenheit and 176 degrees Fahrenheit. Electrical Marketplace electrical tape is 7 mils thick, resists UV rays and is UL-listed.