ArmorAll has many purposes with polymer clay.  It protects your cured clay (and can clean the surface before buffing)   It is also used as a resist when using in moulds and when using texture sheets.

 These 38mm high glass jars offer ease of use.  ArmorAll is usually sold in spray form but is much more useful to clayers in small (20ml) quantities as a paint- on liquid.

Helen Breil has a new tutorial out (you can find it here) in which she explains how valuable it is to use with your textured creations