Philip also developed the concept of the “book wall”; the images on each book flowing on to the covers of adjacent books, front and back, yet also integral across each component book. The first book walls were developed around the text of The Lord of the Rings, by JRR Tolkien; in 1973, he and Tolkien were invited to present one of those special bindings to the Duke of Edinburgh, and it is now in his personal library.

https://www.theguardian.com/books/2019/mar/26/philip-smith-obituary

I do think I have seen this mentioned before, so would be grateful if anyone can refresh my memory, also struggling to see that Tolkien would have been directly involved with this.