Should my natural nails be kept rather short for the application or do the Press Ons hold better with longer nails?

We recommend keeping your natural nails short so that they don't stick out underneath the press-ons.

However, if this doesn't bother you, you could wear your natural nails longer. This will not have a negative impact on their durability. The only important thing is that they are not longer than the press-ons themselves.