Material preview colour

[Nathans]

Hi all,

I've created a glass texture that I like very much, however the problem I can't seem to resolve is that in modelling the glass is a colour, not transparent.

The only setting I can see to change the colour is is under Diffuse, but there's no transparent material to choose from.

It renders out perfectly, however moving through the model, it's important to see through the glass (before rendering)

Any ideas?

Thanks

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