what determies if charge by induction will be permanent or not?

Question

for example when a charged comb attract paper confetti, some confetti remains attracted to the comb. while others are initially attracted but are then repelled upon contact

Answer 1

If some charge is transfered from, say, the comb to the paper, then they will repel each other because they now have like charges. If no charge is transfered, the paper will continue to stick because of the charge polarization.

Answer 2

The particles that fall off usually pick up an amount of charge from the comb and negate the attraction.