Bank of England announces new 20-pound note

The Bank of England has announced an update to its 20-pound banknote with an image of painter Joseph Mallord William Turner (1775-1851). The Turner note will be printed on polymer and will be issued by 2020. The reverse of the note will include:

J.M.W. Turner's self-portrait, painted c. 1799 and currently on display in the Tate Britain.
One of Turner's most eminent paintings The Fighting Temeraire; a tribute to the ship HMS Temeraire which played a distinguished role in Nelson's victory at the Battle of Trafalgar in 1805.
The quote - "Light is therefore colour" from an 1818 lecture by Turner referring to his innovative use of light, shade, colour and tone in his pictures.
Turner's signature from his will, the document with which he bequeathed many of his paintings to the nation.

Below the concept image for the portrait of Turner which will be used on the note. Below that the painting The Fighting Temeraire.