The selection of the backing is as important as the adhesive in the design consideration of the tape. Just as an adhesive bonds two surfaces, the backing of the tape forms the second surface. A tape can be used to hold, join, reinforce, seal, splice, gasket, separate, labels, identify, mount, insulate, reflect, and mask. And the use for which the tape is intended, determines the backing. Whether it must be thin, strong, comfortable, transparent, resistant to organic chemicals, acids and bases, sunlight, heat, cold, compression, all determine the choice of base. Sometimes the only solution is a composite of two or three materials. Similar characteristics will also dictate the design of the adhesive used. It may be that the adhesive bonds very poorly to the backing. In this case, a primer is used.
The tape/adhesive combination must now be converted from sheet form to roll form which means that the adhesive must be protected from sticking to the back of the base carrying it. Occasionally, the base of suitable chemical design so that no harm comes to the adhesive when wound on its own backing and the tape unwinds fairly easily.
However, coating the back of the tape with a suitable protective known as a release coat is usually necessary. This protects the adhesive and gives easy unwind. Using another approach may be either necessary or advantageous; use a release coated paper or plastic to protect the adhesive. With a double-sided tape (one with adhesive on both sides of the substrate), a double-sided release paper or plastic is the primary means of converting the product to tape form.
Note: This material is an excerpt from Shuford Literature.