Altdorf Guard Blue is a Citadel Layer color.

Citadel Layers are high-quality acrylic paints; the Citadel range includes 70, giving you a wide selection of shades to choose from when painting your miniatures. They are specifically designed to be applied over Citadel Base paints and other Layers without the need for mixing. By using multiple layers, you will achieve a rich and natural finish on your models, which will look fantastic on the battlefield.

The bottle contains 12ml of Altdorf Guard Blue, one of the 70 Layers. Like all products in the Citadel range, it is a non-toxic water-based acrylic paint, designed for use on plastic, resin, and metal Citadel miniatures.