Thank you everyone.
I have used it to transfer a drawing of the Dahila which was on the front cover of Ann Pember's book Painting Close-Focus Flowers in Watercolour which I borrowed from my local library. It was surprising that the light was bright enough to come through the cover. Now just have to work out how big I want to draw it and the work out how to paint it slowly as it has many colours.
So I hope the winner of the next challenge enjoys their light box.
