Wilkie's brother Charles was in Paris with his wife Katie Dickens. They had not returned to England after their honeymoon and were living frugally on the Continent.

Sampson Low was publishing Charles's book The Eye-Witness and the enclosure was almost certainly to do with that, perhaps proofs or perhaps relating to the engraving on the frontispiece by Hablot Knight Browne (Phiz) engraved by R Young. Why they were sent via Wilkie is not clear.

This letter is smaller than shown measuring 133x86mm. It is a folded sheet with the partial watermark A PIRIE & | 1860. The rest of the paper is blank save for a dealer's number 2958 in pencil on p.4.