Plumber’s tape is used for supporting horizontal plumbing pipes hanging from joists or other supports. Protective gloves should be worn when working with it as is easy to get cut. Although it is not terribly pleasing aesthetically, usually it will be covered by a ceiling or soffit. Not only that, but it is often mandated by local plumbing codes, so there is no getting around using it.
Traditional tape, used for hanging iron pipe, is a flat galvanized steel or copper strip perforated with a continuous line of holes down the middle and sold in rolls. The holes are sized to allow a ¼ inch number 20 machine bolt. The tape is available in light or heavy thicknesses; for iron pipe, plumbing codes typically require the heavier tape.
An extra heavy 1/16 inch thickness strap is available in ten foot lengths which are double width. It is intended for hanging large diameter iron pipe when specified in local plumbing codes.
100% copper plumber’s tape is used for hanging copper pipe, since steel can cause dielectric corrosion when in contact with copper. A less expensive copper-plated tape is available, but it is known to rust in moist environment and is prone to dielectric corrosion when the plating oxidizes away, so it is not recommended.
Plastic plumbing tape is used for hanging plastic drain waste vent pipe line runs. It can also be used with copper pipe that runs parallel to joists. It comes in rolls of 100 feet in cardboard boxes that act as dispensers.
The advantages of plastic tape include it’s lower price, lighter weight and the smaller screw-holes, which allow you to start a screw in the hole and then leave it there without screwing it all the way in; this helps when working in hard to reach areas.
A disadvantage of plastic plumber’s tape is that it tends to keep it’s coil from the roll, so it won’t lay flat on it’s own when you try to shoot it into tight areas. Nuts and bolts can’t be used since the holes are too small, so you are limited to screws for attachment. Another negative point is that the plastic tapes are usually dark in color and hard to see in some spots.