I REALLY wanted to like this effect as it uses colorful cards and is quite visible to anyone either
closeup or for groups!
The principle of this is similar to other effects and I was really hoping
that was NOT how the gimmick worked.
With that said...it is NOT 100% reliable and you have
to be super careful "how" you spread the cards and display the cards throughout the routine
especially the result at the end.
As far as how long these cards will actually be
useable...not sure as this principle must be handled and stored a certain way to keep it consistent.
Overall a great trick, but certainly overpriced for what you get and for how it is
produced.