No problem Paul! If you make it up to King's Lynn for the opening on Sunday 13th, both Graham Cooley and I will be there all day, so please do come over and say hello!
I think Hlava's designs are rather wonderful, and this particular piece exemplifies the title of the exhibition to me. It is an excellent example of how design processes and ideologies were translated from high end, unique 'masterpieces', down to pieces produced for mass market export.
Some of Hlava's unique designs were blown into wet cardboard or paper enclosures, which burst in places creating a unique form, with randomly sized and positioned bulges and undulations, each time. Hlava was also on hand to accentuate or further modify the form when it was still hot. As well as arguably being an early example of "studio glass", these can be deemed 'Hi Sklo'.
The vases like yours are related to this process, and were produced and exported in considerably larger numbers. We believe that they were probably blown into some form of openable cylindrical wire cage, which gives the curving grooves and undulations. As these vary from piece to piece, there were probably a number of different cage 'moulds', each with a different pattern along the same theme. These represent the 'Lo Sklo' end of this stream of Hlava's work.
Throughout his career, Hlava seemed to have been very interested in the idea of internal and external protrusions and bulges. These either make a particular design cross the boundary between sculpture and functional item, and/or explore the plasticity of molten glass and the optical effects created. One of his early, landmark designs is the so-called 'Hedgehog' vase (a name given by collectors), designed in 1959/60 and produced at the Chlum u Trebone factory (aka Cesky Cristal). For those of you lucky enough (or rich enough) to own a copy of Helmut Ricke's excellent 'Design in an Age of Adversity...' book on Czech glass published by Arnoldsche, see p.176 for an example. These were made with heat-sensitive glass akin to 'Amberina' patented by Joseph Locke in the US. The 'start' colour is a vivid yellow but, upon reheating, this goes through the full range of orange tones into a deep ruby red, depending on how long it is exposed to the heat for.
All interesting stuff, and I'm sure more will be researched and re-discovered in the coming years - this is a truly great area.
All the best,
P.S.; For those new to this area - 'sklo' is the Czech word for glass.