What ink should I use to stamp with the pouch?

Try any ink that you have–dye, pigment, hybrid , alcohol, or even wet colorants like those from Earth Safe FinishesTM or JacquardTM. You may be pleasantly surprised at what you can do, but expect results to vary based upon the type, brand, and media that you’re stamping. If you are experiencing an inking issue, simply do a test first. If the pouch doesn’t help, probably nothing will.