Foam tapes are available in two general types; double side coated or single side coated.  If used as a mounting tape, then the double coated version with pressure sensitive adhesives on two sides of the foam carrier is supplied.  The foam carrier is beneficial because it fills gaps and accommodates variation between the mounting surfaces.  Also on a microscopic level, a foam carrier will help the adhesive wet out and fill the microscopic peaks and valleys of the mounting surface better than a stiffer double coated film tape.  There are many varieties of foam carriers for making tapes.  The characteristics of the foam, coupled with the characteristics of the adhesive will determine which foam tape is best for the application. 

The hardness or softness of the foam is called the foam density and is usually represented in units of pounds per cubic foot (kg/cubic meter).  Another characteristic called the compression deflection will also provide a comparison of the hardness of the foam.  The compression deflection is the amount of force required to compress the foam 25%.  It is measured in pounds per square inch, psi (kilopascal).  The softest foam will always have the lowest density or the lowest compression deflection value.

 A few of the more common types of foam tapes are notes below..

* PCF = Pounds per cubic foot

** check product data sheets because the surface the tape is applied to may have a limiting use temp less than that of the tape.