This permanent, waterproof glacier-white ink pad looks great on Shrinkets shrink plastic when darker colored shrink plastic is used. It is  also good on the gem tone Shrinkets shrink plastic . See the free tutroal page on how to successfully use inks  to stamp on Shrinkets  shrink palstic 

3" x 2"  Opaque Acid free Ink 

Ranger Glacier white permeant ink pad