In the process of completing the 1991 painting Pedestrian Tunnel, Christopher Pratt made a number of different studies for a number of different purposes. He says:

"I did a number of sketches based on experiences in airports and hospitals and tunnels underground. Then I started drawing curves intuitively, erasing and refining, trying to describe a vortex and a sense that the thing went on forever, never resolving, that there was nothing at the end of it, darkness nor light, that it could only return into itself. When I could feel the tunnel at my back, I used a tracing paper overlay to analyse the lines - I wanted the perspective to be logical. Then I enlarged the curves onto a canvas and drew in the lights and tiles and Jeanette got at the underpainting while I was finishing Black Pickup. I had done a colour study in which the tunnel looked hi-tech, as if it were extruded stainless steel, but that didn't work - it was too surrealistic to be disquieting. My nephew Matthew Ryan saw it and said, 'Hey, Darth Vader - wow': he is a young man with Down's Syndrome, blessed with gifts of observation, if not tact. I brought it 'back to earth' - I have been in hospitals, but not to outer space."

If the above quote from a book called Christopher Pratt: Personal Reflections on a Life in Art illustrates anything, it is the necessity of the study process to a finished work. Have a look at the following studies.

This first study is simply a general study for the work. You can see the different types of lines and grids that Pratt uses in the study process. Several such general studies may be done for any particular work.

This second study for the work develops the perspective for Pedestrian Tunnel. In it, Pratt once more uses his knowledge of geometry, mathematics and drafting techniques, this time to analyse the perspective of the work.

This colour study for the work led to the underpainting that Pratt, with the input of his nephew, felt was becoming too surrealistic. You will notice that this study does not contain any grid lines. Studies such as this are used to define the overall concept of the work.

This is the study that the artist made to change the look of the tunnel. Notice the squaring of the lights, the angling of the wall to ceiling, and the details in the floor.The study was also used to ensure that the lines as the corridor curves are consistent and that the spaces between the lights in the ceiling get smaller as the tunnel curves off into the distance.

Don't forget to have a look at the finished work, Pedestrian Tunnel. Notice how the changes made in study four are incorporated in the finished work.