The huge hole then needed to be flattened and stabilised. A canvas insert was cut and installed into the hole to re-create the original texture and appearance. The edges of the tear were glued back together for strength. Any final small holes were filled from the back.
Picture: preparing the lining canvas with glue
The canvas was then re-stretched onto its original stretcher and the new patch was inpainted to match the original canvas.
This treatment was very successful. The central canvas now has as much of the original painting showing as possible. It is stable and the tear is no longer visible. The re-touching and damage should be almost invisible to anyone in the cathedral.
The final picture after treatment will be uploaded once the scaffolding comes down and a picture can be taken from below.