Additional heating, or firing of the natural earth pigment creates this darker variation of a classic Sienna earth color ASTM Lightfastness I (Excellent); Semi-Opaque; Pigment(s): PBr7 (Calcined Natural Iron Oxide); Vegan PROFESSIONAL QUALITY colors combine the durability of acrylics with the versatility of ink, great for drawing, staining, dripping, pouring, calligraphy, color washes and spraying EXCEPTIONAL UTILITY – Formulated with flow improvers and retarders so colors are ready to use in dip pens, refillable markers or airbrushes with no thinning required. Made in the USA with globally sourced materials by an employee-owned company with more than 40 years of experience making paint for professional artists HIGH FLOW ACRYLICS are an ultra-thin paint with ink-like consistency that provide incredible versatility. They can go directly from bottle to airbrush, refillable marker or dip pen and work great for drawing, staining, dripping, pouring, calligraphy and color washes. High Flow offers a palette that includes many single-pigment colors, as well as Fluorescent and Iridescent colors. While it acts like an ink, it’s an acrylic so it's compatible with other GOLDEN Acrylic colors and mediums.