Senior Conservator David Wise analyses Blue poles in situ during the COVID-19 closure of the National Gallery

David and National Gallery Director Nick Mitzevich inspect the Jackson Pollock masterpiece

Pollock’s thumbprint can be seen in the detail

The house paint Pollock used in Blue poles is key to the conservation

Items such as glass are embedded in the painting

A piece of cardboard in the work of art

Microscopes and Infrared lights were used during analysis

David Wise has spent weeks analysing Blue poles up close