Cloud Extension is a long white cloud, spread low across the horizon, comprised of birds. Blackbirds have an important place in many different mythologies around the world, they often represent a transition between worlds, perhaps because they sing both day and into the night and spend much of their time on the ground. They represent shift between spaces: between day and night, between land and sky, between heaven and hell. Cloud Extension is made in a complicated glass-casting technique called pate de verre, in a press-mould, the result is a semi-transparent thin glass relief sculpture with bird imagery on one side and rolling hills on the other, the thick and thin transitions of the glass grains have the density of gathered precipitation, allowing light to filter through between bodies and gaps, like a cloud.