In looking at the specs for two types of 3M Automotive Tape, you’ll see two different levels of adhesion. So, what is adhesion, and what does it mean to tape buyers?

First, adhesion (as in adhesive) refers to the degree of stickiness exhibited by tape. Consider, for example, the difference between a PostIt Note and duct tape. The first can easily be pulled away, while duct tape demands that you pull hard if you want to take it off. We would say, then, that the PostIt Notes exhibit low adhesion and duct tape exhibits high adhesion.

And since we have all kinds of uses for tape, and can have different time spans in mind, it makes sense to choose the adhesion level that works best for your purposes. If you’re tacking a small piece of chrome onto your dash, you might use something like 3M Automotive Attachment tape. On the other hand, if you’re sticking a fender back on your ’57 Chevy, then you’ll want 3M’s VHB tape, which is strong enough to compare with light riveting or spot welding.

How can you tell which is which, when it comes to choosing a type of tape? Look in the technical specifications section and compare the numbers of the descriptive terms used. For example, ‘good’ adhesion refers to a lighter or less sticky tape, and ‘high’ or ‘excellent’ refers to a stickier tape, one that’s harder to pull away from the surface to which it’s attached.

This bonding strength isn’t the only factor to consider in buying tape, but certainly ranks as critical. After all, if you can’t get it to stick one thing to another, it does you no good.

Incidentally, do you know the difference between ‘adhesion’ and ‘cohesion’? As Benjamin E. Russ is of the University of California at San Diego explains in Scientific American, “There are two fundamentally different components of tape’s sticky nature; adhesion and cohesion. Adhesion is the binding force between two different materials, whereas cohesion is the binding force between two similar materials… Hence, the ‘stickiness’ of tape is caused by a combination of the molecular forces of the glue material sticking to itself as well as holding onto the substrate.”

Take a moment next time you’re shopping for 3M Automotive Tape, or any other type of tape, to consider the key role of that sticky stuff on one or both sides of your tape.