River Avon Book has a black front cover on which the words ‘RIVER AVON BOOK | RICHARD LONG’ are handwritten in white pencil crayon. The book has around thirty off-white, hand-made pages with torn edges featuring horizontal streaks of light-brown mud. On some pages the mud streaks are thicker and darker while on others they are thinner and more mottled, evoking rivulets across the pages.
Long created the pages of this book by dipping sheets of paper into silty wet mud taken from the River Avon in Bristol. He then hung up each sheet to allow the water to run off, leaving streaks of dried mud on its surface. These papers were then hand-bound into a book. The artist has explained:
I think the first mud work on paper was River Avon Book of 1979, where I had the idea to make this book with the pages dipped in muddy water. So I got all these sheets, quite big sheets, and after they had been dipped in the muddy water they were cut down and bound into these books. That was the first time I used paper with mud on it…