Oil on canvas, stretched and ready to hang.
Signed on the back.
Freeze in its current form was exhibited in a show called Three Painters. There is a clear division on a larger scale of two surfaces of curved shapes and an interplay or tension between the two surfaces of which is on top and which is the ground. While the division was in place for much of this paintings history, there was a slow revelation to the final internal stoke's placement and colour.
There are two other paintings started around the same time, namely Fight and Flight.