Permanent on all surfaces ...The stamp pads are water-soluble, acid free,rchival, lightfast and washfast.  They are designedfor use on many surfaces, such as paper, fabric,shrink plastic, clay, leather, glass, wood and others.  The Pearl Ex Stamp Pads are available in 12 colors in fourgroups: Two-Tone, Metallic, Interference & Essential Colors.  Re-Inkers also available.