It is a safe, non-toxic, inert powdered pigment with a neutral pH. It is extremely colour fast and stable — it will not tarnish or fade and is therefore ideal for archival applications.
Duo colours - these powders are different colours on different polymer clay backgrounds - the first colour shows on light clay and the 2nd colour on dark clay.
Interference colours - look white before application but give a strong effect on dark polymer clay ranging to pastel on white clay.
Pearl white on white polymer clay makes wonderful pearls. The same colour on black clay gives a beautiful bright silver.