Xstamper recommends Xstamper Refill Ink only be used to re-ink Xstamper and XstamperVX pre-inked rubber stamps. It has been specifically formulated to flow cleanly through the micropores of the Xstamper's laser-engraved rubber impression die. Using ink other than Xstamper Refill Ink can clog these micropores and voids the Xstamper lifetime warranty.