It's nearly four years since the Birmingham Hippodrome reopened after its #30 million makeover, but it's only recently that a finishing touch has been added.

Liz Rideal?s 11-metre glass lantern, which now hangs in the stairwell, provides a counterpoint to her decorative glass wall looking out over Inge Street and the Hippodrome?s newly restored neighbours, the Birmingham back-to-backs.

The two components share the same imagery of curtains ? an appropriate choice for a theatre.

?The whole idea of curtains and drapery is complicit with theatre,? Rideal says. ?There?s the old Hamlet-Polonius thing of lurking behind the curtain, that slightly voyeuristic Peeping Tom thing of listening and looking.?

But, also in keeping with the spirit of theatre, all is not what it seems.

? These mighty curtains, blown up to an epic 15 x 8 metres in the windows, belie their modest origins.

Rideal explains: ?I?ve been working with photobooths for quite a while now. I took my Auntie Kit?s old bedspread into a booth to photograph it, did a bit of Photoshop on the image and then that was sent up to Sunderland and they enlarged it and printed it. They mix some ground glass with pigment and then the whole thing is put into an oven.

?I?m very interested in processes, whether it?s bronze casting or monotype printing, screening on to glass, or putting a glass piece together. They can all suggest new ways of making work.?

Rideal works in a variety of media including sculpture, prints and photographs, but this is her first work in glass.

?I?ve always wanted to do something in glass ? my mother used to import glass into this country and we used to have lots of it around. I started looking around the museum here and they have a most fantastic thing, which is a fragment of the crystal fountain by Oslers that was a centrepiece of the Paxton building that was in Hyde Park originally and then transferred to Crystal Palace.?

However, the idea for the lantern, which is made up of 16 boxes each comprising four pieces of glass, was inspired by Brancusi?s Endless Column.

Public commissions often take a while to deliver, but this has taken longer than most, delayed by the need to raise additional funds. The first drawings were done eight years ago.

As it happens the delay hasn?t been a major problem for Rideal, who has found the process a smooth, if unusually extended, one.

?What was really good about this project was that the architects weren?t fearful of working with an artist. That?s quite often the case, but they were great.?