The overall effect of a tunnel book is to create the illusion of depth and perspective. The openings in each page allow the viewer to see through the entire book to the back, and the images or calligraphy on each page work together to create a 3-dimensional scene inside.
This type of book dates from the mid 18th century and was inspired by theatrical stage sets. Traditionally, these books were often created to commemorate special events or sold as souvenirs of tourist attractions. The tern 'tunnel book' derives from the fact that many of these books were made to commemorate the building of the tunnel under the Thames River in London in the mid 19th century (not looking through a tunnel, as I previously thought.)
The Tunnel books that we will be making are cased into a cover board. The cover board allows the tunnel to be displayed easily as well protecting the folded tunnel.