Kuretake Gansai Tambi Watercolor No.663 OPAL BLUE

The Kuretake Gansai Tambi No. 663 Opal Blue is a single Japanese watercolour paint in a large pan format – pigmented with mica, which gives the blue shade its characteristically shimmering, pearlescent quality. On white paper, the colour appears as a delicate, pearly blue tone; on dark paper, it reveals a rich metallic sheen that shifts with the viewing angle. The Gansai Tambi line continues the tradition of Japanese watercolour paints: water-based, hand-crafted in Japan, and drawing on over 100 years of experience in sumi ink production at Kuretake.

Features

• Mica pigmentation: Glitter pigment creates an iridescent pearlescent effect – the colour appears more or less intensely blue or silver-shimmering depending on light and viewing angle.
• Two surfaces, two effects: On white paper, it produces a delicate, pale opal blue with gentle lustre; on dark or black paper, the metallic-luminous character of the colour comes to the fore.
• Variable coverage: Applied with little water, the colour appears opaque and intense; diluted heavily with water, it creates a transparent, glazing opal shimmer – comparable to a blend of watercolour and gouache.
• Large pan format: The pan measures 48 × 28 mm and offers plenty of surface area to load wider brushes comfortably and colour larger areas.
• Compatible with other Gansai Tambi colours: Opal Blue mixes with transparent Gansai Tambi hues – creating not a simple colour blend, but a secondary colour shimmer that appears when tilting the paper (colour-shift effect).
• Non-toxic, water-based: Water-based pigments, acid-free, ACMI-certified.

Use & Tips

• Activation: Circle a damp brush or water brush on the pan until the desired amount of colour releases. The colour activates quickly and requires no lengthy soaking time.
• Calligraphy and brush lettering: Opal Blue is excellent for lettering work on dark paper or card – the mica content ensures that even thin strokes shimmer metallically.
• Illustrations and watercolour backgrounds: Applied as a glaze over dried watercolour, Opal Blue adds a second optical layer – the blue tone appears subtle or luminous depending on light.
• Mixing effect with transparent colours: Mixing Opal Blue with another hue doesn't produce a simple green or grey tone, but a base colour with secondary blue shimmer – ideal for vibrant, shifting mixed tones.
• Dark paper: On black or deep blue paper, Opal Blue's metallic character is strongest – suitable for cards, mixed media and lettering projects.
• Lightfastness note: Lightfastness is pigment-dependent; with mica-based colours, lightfastness decreases with increasing water content. For long-lasting work, apply more concentrated.

For Calligraphy Enthusiasts

Opal Blue is based exclusively on mica pigment (no additional colour pigment like PB15 or similar), making the colour a pure interference tone: the colour is created through light refraction on mica layers, not absorption. The result is a blue tone that appears subtle and transparent on light grounds, but opaque and metallic on dark grounds – a behaviour not achievable with classical watercolour pigments. For calligraphers working with brush and water brush, the creamy consistency of the pan is an advantage: the colour flows evenly from the brush without clogging or lumping, making it suitable for finer letterforms.

Technical Specifications