Last time we spoke I mentioned that I would tell you about the different type of glass I use in lampworking. I use mainly soft glass (also known as soda lime glass) & it can have inclusions in it like silver & gold which gives you a different effect when you melt & then work it. It is also called 104 glass which, without going into great detail, means that it's Co-efficient Of Expansion (the amount the glass expands & contracts when it's heated) is 104. This is very important as, in general, glasses with different COEs don't play well together & if mixed will often develop incompatibility cracks throughout the bead. That is a very simplified explanation of what is a very involved & complicated subject but it's probably enough for you to understand the general gist.
Soft glass comes in 2 main types - opaque & transparent. Opaque glass is in general softer than transparent glass & includes colours like white, ivory as well as opaque shades of all of the colours of the rainbow. There are some colours that are not very well represented in the 104 colour spectrum, a hot/intense pink is one hue that can be difficult to find as is an intense lavender/purple (for those Aussie's amongst us, the colour of jacaranda flowers).
Transparent colours are in general much stiffer than the opaques & can be harder to work, depending on what you are doing with them. One application where transparents are superior to opaques is sculptural pieces, the extra stiffness that the transparent glass gives means that you can keep the piece warm more easily without melting all of the features into a blob like you are more likely to if you use a soft opaque like white or ivory. One surprising fact is that the most common forms of black glass is actually a very dense transparent dark purple & if applied thinly it dilutes back to it's base colour (reddish purple). To combat this glass manufaturers have made a couple of "true" blacks, the most well known of which is Intense Black.
But apart from those few small chinks in the colour pallete, soft glass has an amazing range of colours & is one of the most popular lampworking glasses in use today.
Next time, we will discuss the silver glasses & their use.