A hybrid of UTP and STP is screened UTP (ScTP), also known as foil twisted pair (FTP), or pairs in metal foil (PiMF). This is shown in Figure . ScTP is essentially UTP wrapped in a metallic foil shield, or screen. It is usually 100-ohm cable.

If improperly grounded, or if any discontinuities exist in the entire length of the shielding material, (for example, due to poor installation) STP and ScTP become susceptible to major noise problems. This is because noise problems cause the shield to act like an antenna picking up unwanted signals. This effect works both ways. Not only does the foil prevent incoming electromagnetic waves from causing noise on the data wires, but it also minimizes the outgoing radiated electromagnetic waves, which could cause noise in other devices. STP and ScTP cables cannot be run as far as some networking media, such as coaxial cable or optical fiber, without the signal being repeated. Also, more insulation and shielding combine to considerably increase the size, weight, and cost of the cables. The shielding materials make terminations more difficult and susceptible to poor workmanship. Despite their shortcomings, STP and ScTP cables are still useful in high electrical or RF noise environments, such as near an airport radar installation. These cables are also popular in Europe.