Amethyst and smoke/grey Bolle vase designed by Tarpio Wirkkala for Venini in the 1960's.
 
This example is a pale early example, the intensity of the colours has changed over the decades and this piece is still made by Venini today.
The Finnish artist and designer started working with Venini in 1962, in 1966 he designed the Bolle series of glass bottles in various shapes and colourways. Each bottle was made using the complicated and exacting 'incalmo' technique. This process is particually difficult as the upper and lower parts of the piece have to be shaped and joined perfectly whilst the glass is still hot, there is no margin of error.
 
The book, 'Italian Glass Murano' 1930-1970 by Helmut Ricke and Eva Schmitt (page 341) states that the combination of 'vibro-pen', company and artist signature were employed on a few productions supervised by Wirkkala.
 
Signed Venini Italia TW