Historically a very expensive ground lazurite pigment, synthetic pigment has been used since the 1830's making it one of the most popular and affordable blues, Yves Klein blue is mostly Ultramarine.

Pigment Classification: Inorganic
Color Index Name: PB29
Color Index Number: 77007
Chemical Description: Polysulfide of Sodium-Alumino-Silicate
Opacity/Transparency: Semi-Transparent
Lightfastness Rating: ASTM 1
Permanency: Not for Exterior Use
Munsell Notation Listing: N/A
Gloss Average: N/A
Viscosity Range: 75-100 CPS
CIE L*a*b* Values: N/A
Tint Strength: N/A

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.
 
• Detailed Product Information
• Pigment Information
• Safety Data Sheet [PDF]