Purple Rose G199 & Royal Purple G198 tutorial .. thanks Michael Hengler

- Michael Hengler . com - https://www.facebook.com/michaelhenglerartist


Following on from the outstanding success of Gaffer's Duro series (See Lino Tagliapietra  and  Michael Schunke for instance) where we strongly emphasized the working characteristics and properties of the glass rather than the colour, we are really delighted to announce the new Alabaster/Opalino series G-160 - G-168. These are glasses that exploit the magical, soft fiery properties of phosphate opals and are now available to the glass blowing community for the first time.
Firstly, we were fortunate to have already perfected a phosphate opal base which conquers the problem of "heat rings" which we see in our competitors' Opaline/Alabaster. Gaffer's G-190 Alabaster doesn't exhibit any thermal history of different opacities depending on glory hole heating. 
Secondly, we decided to bring to the series soft pastel shades which contrast with the rather hard and sharp colours of the fluorine opals. Phosphate opals really are suited to gentle pastels.
The phosphate opals have an interesting history. The first known examples showing phosphate as the primary opalising agent are Syrian and Persian glass examples from the 14th century. In Europe the use of bone ash as the source of calcium phosphate in these opals had previously been thought to originate from the researches of the great glass chemist Johannes Kunckel, who was largely responsible for reviving gold ruby, but it is believed that several German alchemists were in receipt of this discovery around the end of the 17th century and they may have gained the knowledge from the Italians. The Venetians had a close trading relationship with the Mamluk dynasty who ruled Syria up until the end of the 15th century and it is likely this was the conduit for phosphate opal recipes.
One of Kunckel's contemporaries, Becher, was rather over awed by the fact that human bones could render glass a milky opalescence and in his book with the wonderful name Subterranean Physics he wrote:
 "Oh, how it should be of custom that I would have friends to serve my dry bones, exhausted from all of life's work, this last of all duties, and transform them into this never changing timeless substance, glass, the softest colour of its kind...., the trembling Narcissus' milky reflection, possible to be done in some hours only, so as to become the evidence of God's almighty power on the day of resurrection and illumination"
Apparently Becher carried around a small phial of powdered human bones and was reluctant to make the secret known for fear that such an awful revelation may lead to its misuse.
The widespread use of animal bones in glass, particularly in Bohemia in the 17th and 18th centuries, (where this type of glass was known as Venetia glass) was due to the general trend of trying to make glass imitate Chinese porcelain and bone china. In the early 20th century sea bird droppings, guano, became a popular source of calcium phosphate. However, since the industrialisation of glass making, phosphate opals have been almost abandoned except for producing low expansion borosilicate oven ware. Manufacturing problems for soft phosphate opal glasses arise from a propensity to devitrify easily and the high forming temperatures that are required to stop large crystals forming. This leads to rather painful gathering conditions for our bar making crew, but we think the results are worth it.
Gaffer Glass believes this is the first time a phosphate color range has been available in rod or chip form that offers sufficient opacity as a flashing or casing colour, is fully compatible with the common clear glasses used in the studio scene and is free of faults such as heat rings and rogue crystals.
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