The red ink will bleed off of Chipcos onto anything they come into contact with. PVC flips are the worst offenders for several reasons. The plastic conforms to the chip and makes excellent surface contact. Once the ink is in the plastic, it spreads. It will migrate and transfer back onto the chip causing a "blurring" effect.

It is my experience that airtites mitigate all of these effects. The hard plastic makes a minimum of direct surfact contact. Once on the plastic, the ink won't migrate.

If your chip has any value at all, it's worth 30¢ to protect it.