After reading a lot of differing opinions on backdrop materials, I decided to try 0.060″ sheet styrene. The best reference on sheet styrene backdrops is Marty McGuirk’s Back to Basics column in the April 2000 Model Railroader.
I had some difficulty locating a company that would cut a 4’x8′ sheet of styrene into 3 16″x8′ sheets. I finally found Commercial Plastics here in Calgary who did the cuts for no additional charge.
I decided on 12″ radius corners at each of the three corners of the module. In order to line things up easily, I marked the wooden module structure at key places. I then calculated the linear distance of backdrop need to match up with this point (using the rule that the circumference of a circle = 2*pi*radius; therefore the length of a 90 degree curve is pi*radius/2). Then I just put the styrene in place, matching up the marks as I went.
I used latex contact cement to glue the styrene to the wooden module structure which worked very well. Because a single 8′ section was not long enough to fit the module, I spliced two sheets together with an 8″ splice plate between them. I used styrene putty to fill the small gaps at the splice. Here’s a photo of the backdrop while the cement was drying:
At the left side exit of the module, I built a little flap of styrene to cover a very unattractive view of the benchwork which can be seen here:
One thing I would do different on the next module is to give the styrene a light sanding with a fine grit sandpaper before installing in the module. It is relatively easy to chip the paint on the unroughed sheet styrene. Touch wood; I have not scratched anything yet but the potential is there. Roughing up the surface would give the paint something to adhere to.