I reckon the easiest way to do this is with a vector programme -
Inkscape is open source/free, will probably do the job.
Draw one line, make it a heavy line.
Then duplicate it/clone it - but make the second line thinner and make it white.
The result will be like this:IDEA: Auto draw 2 lines about 1 inch apart & curve around but not overlap.
if you want, I could produce a vector PDF for you -
but give me some more details.
I can make it any size you want - in the latest Adobe Reader (version 'X') you can print an extra large image on as many pages as it needs -
you get a bit of a jigsaw puzzle after