Who you purchased the flips from really does not answer the question. Many manufacturers of flips use pvc chemicals in order to soften or make the flips pliable. Usually, non-pvc flips are hard and brittle, but they will not make the chips discolor or show a bleeding into the flip pocket that is in evidence if you remove the chip.

Also, do you clean your chips with a detergent? If so, do you thoroughly rinse the cleaner completely off the chips under water and allow them to air dry before putting them in the flips? Any of these conditions will make chips discolor years after they have been stored. The soft flips with pvc are generally not intended for long term use. They are designed for inexpensive short time protection against scratching and rubbing against other chips to put chips in for mailing, or transporting home from a show, or for dealers to temporarily insert chips in for sale in a showcase, etc. There was a pretty extensive thread on pvc in plastic flips that can be researched in the archives at www.ccgtcc.com. Good luck.