Most of the tapes that Viadon carries utilize a "pressure sensitive adhesive" system, or PSA.
This adhesive system is designed to require pressure to activate the adhesive that will,
quite literally, "flow" over time into the microscopic crevices of the substate material
(i.e., the surface to which the tape is applied). This is called "wetting out", though it
does not actually refer to the adhesive being wet or even any liquid being involved -
it is the process of the adhesive flowing into microscopic crevices, along with removing air bubbles.
This is why applying pressure is so important for pressure sensitive adhesives.
Most tape manufacturers recommend a minimum of 24 hours for best adhesion and up to 7 days for
maximum adhesion (though the 24 hours timeframe is usually sufficient for most applications).
PSA's are of benefit in situations such as anodizing and/or plating, where a substrate is immersed
in fluid for a metal finishing process. The additional time allowed for the adhesive to flow into
microscopic features of the substrate creates a sharp cut off line for the anodizing / plating process.
The additional time may require an overnight wait for full adhesion to occur (anodizers in particular),
but can avoid costly rework and get the job done right the first time.
Above all, the key is very often one important point if maximum adhesion is needed: When applying
the tape, PUSH DOWN, hard.