A non-toxic, water-based, acrylic wash manufactured by Games Workshop.
Specially formulated to flow seamlessly into gaps, crevices, and recesses on plastic, metal, and resin miniatures to create realistic shadows, define fine details, and accentuate highlights. 
Contains white pigments that settle quickly; the pot requires extensive shaking before use to ensure even distribution.
Highly effective for adding subtle depth, shading, or distinct character to white armour, fur, and snow or frost effects. 
While formulated to work straight out of the pot, it can be thinned down using water or a dedicated shade/glaze medium to help it flow better over large, flat surfaces without pooling