Vertu has revealed a collection of four one-off Signature handsets decorated using the technique of maki-e on urushi lacquer by Kazumi Murose.

Urushi, or Japanese Lacquer, is an ancient art form, dating from around 7,000 BC and is created by layering and curing resin from the urushi-no-ki tree.

The Kissho collection has been created using this technique with the application of maki-e, an intricate art form achieved by sprinkling tiny particles of precious metals, predominantly gold or silver, onto the urushi lacquer.

In the creation of the Kissho collection, the technique of raden has also been used, which involves either inlaying thin slivers of mother-of-pearl into recesses in the urushi or adhering pieces to the surface of the lacquer.

A series of carefully planned and executed steps is required to create an effective design in maki-e and raden. In the case of the Kissho Collection, these steps were as follows:

The urushi coating: A base coat of urushi mixed with gold powder was applied to the gold handset pieces. This was then heated to 150 degrees centigrade and then cooled. When set, the pieces were burnished using charcoal.

The cycle of application, heating and burnishing was repeated eight times, the second and subsequent urushi coatings being mixed with pine soot. This method produces a smooth, flat, black urushi surface.

Copying the design: The design, drawn on a thin sheet of Japanese paper, was traced in coloured urushi from the back of the paper and then transferred to the handset parts. A very fine gold powder was then rubbed on, revealing the design.

Backing the mother-of-pearl: The mother-of-pearl pieces for the Nanten berries were backed with gold coloured silver leaf using urushi as the binding agent. These were then heated twice in a furnace. Platinum powder was used to back the other shell pieces. These were then cut into the desired shape.

Attaching the mother-of-pearl: The mother-of-pearl pieces, coated with urushi on the reverse, were arranged on a thin sheet of Japanese paper and then adhered to the handset parts. Thicker pieces were set into recesses in the metal body of the part.

Sprinkling on powder: The design was painted in urushi, using a maki-e brush which has very long, thin, strong bristles. Gold powder was then sprinkled on to the wet urushi using a funutsu, a tube-shaped tool made from the shaft of a crane feather.

Coating with urushi: Urushi was then painted over the sprinkled gold powder to set it. Then the entire surface of the piece was coated in urushi, hiding the design beneath this layer.

Polishing and burnishing: The excess urushi was then removed with a special soft charcoal, revealing the design. This cycle of applying and removing urushi was repeated several times. The piece was polished several times using whetstone powder and oil and was given a final polish with a fine powder made from steamed deer horn, revealing the completed design.

These four unique phones are a result of two years of close collaboration between the craftspeople and engineers at Vertu and Mr Murose.

Mr Murose has used traditional Japanese symbols of good omen and good luck, naming and associating each of the handsets with one of the four seasons.

Daigo (Cherry Blossom), Kinko (Brocade), Kikusui (Chrysanthemum) and Nanten (Nandina Domestica) are all deeply rooted in the lives of the Japanese and their quintessential appreciation of the changing seasons.

Each also corresponds to one of the four seasons - spring, summer, autumn, and winter.

Click here to see how they are made.

Photos: Vertu