Bullseye
Which glass should I use to make beads from?
There is a bewildering assortment of glass out there from which to make beads at the torch. The simple answer is - use whichever glass is easiest to find for which you like the colour range or which suits your budget. Of course the considered answer is more complicated than this. Firstly, let’s look at the form that the glass is in. Glass that has been developed for use in a torch flame is normally in the form of rod. The rods of glass are nominally 1 metre or so long and between 3 and 10 mm thick. The glass has been pulled from a mass of molten glass as a thick thread, so the resulting rods have a circular cross-section. There are several manufacturers of glass rod but there are only 4 that I have worked with to a greater or lesser extent. These are
Plowden and Thompson (English)
Effetre (Italian)
Bullseye (American)
Satake (Japanese)
Plowden & Thompson
P & T are based in Stourbridge, West Midlands. They supply 2 ranges of glass, based around 2 different coefficients of expansion, 93 and 100. There is a good choice of colour for both ranges, though there is a wider choice of transparents in the 100 series.
The glass is a bit stiffer than Effetre, which makes it good for keeping surface detail but is slower to work with. I use a Nortel minor torch; if you use a Hot Head you might find it takes significantly longer to make a bead.
P & T glass is competitively priced.
Effetre
This is the major manufacturer on the island of Murano, Venice. Glass beads have been lampworked in this city for a good 400 years. The glass has a mean coefficient of expansion of 104. There is a wide colour choice, though be warned, the opalino and alabastro ranges have a reputation of not working wonderfully well with the rest, though I cannot confirm or deny this as I do not use them significantly.
Effetre is a much softer glass, in that it melts quickly and most colours stay soft over a wide temperature range. Surface features melt in very quickly with a Minor burner and it is quicker to make a bead on a Hot Head.
It is a little more expensive than P & T, with the hand pulled colours being much more expensive.
Bullseye
This is manufactured in Portland, Oregon. Bullseye make flat glass as well as rod with the same coefficient of expansion, 90, and it is the glass of choice for many of those who wish to make lampworked details for inclusion in fused pieces. The colour palette is different from P & T’s and Effetre’s, the opaque colours mostly not being quite so opaque and some colours especially being deliciously acidic.
Bullseye is stiffer than Effetre and does not stay soft over the same wide range of temperature, so beads are quite slow to make with a Hot Head torch.
It is more expensive than the two above in this country.
Satake
Satake has a high coefficient of expansion approximately 113 - 120. There are lead free and lead-containing colours, including some really nice transparents but it is not advisable to mix the two. It is very soft, melting very quickly. I would think that it would work well in a Hot Head flame but I have not tried it. With the Minor, the flame needs to be quite soft and the working area further from the torch, i.e. cooler.
It is hard to get in the UK and very expensive.
Other glass rod manufacturers
There are several other manufacturers, including Lauscha (German), Czech and Vetrofond. The latter is interchangeable with Effetre, having COE of 104. Lausha clear is supposedly compatible with Effetre too and is optically good. It was popular as an alternative to Effetre clear which was acknowledged to be prone to scumming. Personally I have never found a need to get into it as I never did much encasing until recently; I think the batch I have must be improved, as it seems fine.
The colour palette of these varieties is limited.
Using sheet art glass
There are a number of producers of sheet art glass and their products can be used to make beads. The glass needs to be cut into strips or small pieces. There are, however, two serious snags.
Strips of glass are more prone to shocking in the flame and the sharp edges can make little clouds of bubbles a problem, especially with transparent glass.
Not all sheet glass is compatible. If you use scrap glass (really cheap) from your nearest stained glass supplier you can’t mix colours without doing compatibility tests. The exceptions are the art glasses used for fusing, such as Bullseye 90 and Spectrum 96. These glasses are tested compatible within ranges at the factory, so if you are sure of the source you should be OK.
Scrap glass from bottles etc.
It is possible to cut up wine bottles into strips and use those. I have tried it, to get a wide range of greens. The same arguments apply as for sheet art glass but with one additional disadvantage. The glass is difficult to work also because bottles are made of glass which stiffens up quickly out of the flame – well, it has to, if you think about it, otherwise you’d see lots of very deformed, partially slumped bottles on the shelves, wouldn’t you?
Finally There are glasses out there which I have not discussed, such as Reichenbach and Kugler from Germany and Uroboros from Portland, Oregon. The omission is because I have little or no knowledge of these products, not because of their suitability or otherwise.
All information on this page comes from: http://www.glass-beads.co.uk/Flame/June06/WhichGlass.html (accessed November 2008)
