The oldest tapes — masking, electrician's, box sealing, duct, and household cellophane — come without a liner.

Next is the so-called one-side-coated or single-faced tape. Usually, it consists of a flexible material with pressure-sensitive adhesive to bond it to a substrate. The face may be decorative, printable, protective, and so forth.

Then, there's two-side-coated or double-faced tape. It is used to join or bond two substrates, often replacing mechanical fasteners or liquid glue. The two adhesive layers can be the same or different adhesives. The adhesives can be thick or thin. The carrier membrane can be paper, film, foil, cloth, or foam.

Double-faced tape can bond similar or dissimilar surfaces. It's often used in an intermediate step where it bonds to a single substrate that then gets processed (e.g., die-cut).

Double-faced tape can be the primary means of fastening or used to temporarily hold substrates together during assembly. Some examples are the bonding of gaskets or insulation materials, joining electronic components, and attaching molded and extruded-plastic parts.

The fourth is transfer tape or free film, which has the same basic function as the double faced. However, this formulation does not have a carrier membrane to reinforce the adhesive. As a result, the adhesive is extensible and more conformable. With only one layer of adhesive, the tape can be relatively thin.

This tape comes in various thicknesses to fill the gap between substrates. Applications include mounting nameplates and printing second-surface signs or labels. Double-faced tape can also be applied to substrates that are extensible and conformable without significantly affecting those properties.