Horadam colors can be lifted from a dried palette without forming small bubbles. Colors flow evenly and are fully intermixable. Horadam helps the artist maintain full control of color, even on softer papers.
Color Swatch created using heavy application/diluted application and was applied on cold press watercolor paper (150 lb) material.
This extremely lightfast deep blue color is more reddish than Cobalt Blue Light. Coarse-grained, its hue and chemistry resemble the historic Smalt Blue. It is often used to paint the sky and the horizon. Schmincke rates it 5 stars out of 5 for lightfastness. It is semi-transparent and semi-staining.
cobalt(II) oxide + aluminum oxide
CoO + Al2O3
Cobalt blue is a semitransparent pigment with low to moderate tinting strength. When it dries, it appears lighter and less saturated. Pigment particles are large and grainy. Differences in how the pigment is ground and mixed lead to considerable differences in its performance among various manufacturers.
Cobalt blue is absolutely lightfast and extraordinarily stable. The stability of cobalt salts at high temperatures make them the standard for blues used in ceramics and glassware.
Cobalt salts are toxic. Avoid respiratory and skin contact. Soluble cobalt may cause irritation and allergic reaction through contact with skin. It is considered a possible carcinogen.
Since ancient times, smalt blue has been used to color glass and ceramics. Cobalt salts, which give smalt its characteristic blue color, were identified in the 18th century. Techniques for manufacturing Cobalt Blue, a chemically pure salt of cobalt and aluminum oxide, were developed in 1802.
cobalt zinc silicate
Cobalt-zinc silicate is semi opaque and semi-soluble in water. It produces a warmer and darker blue that standard Cobalt Blue (PB28), and is used most often in glass and ceramics.
Cobalt-zinc silicate is extremely lightfast and temperature stable.
Cobalt-zinc silicate is toxic, and its toxictiy may be of greater concern that for Cobalt Blue (PB28) because it is semi-soluble in water.
Since the discovery of processes for mining Cobalt Blue (PB28) in the 19th century, additional processes for manufacturing and purifying other cobalt salts have become available. Their use as artist pigments has followed.
Cobalt Blue Deep
® Schmincke is a registered trademark.