Peter designed the gate layers by first sketching out the idea on paper and then creating the final version in PhotoShop in five layers, each a slightly lighter shade of grey. These were stacked up to give an approximation of how the gate will appear when assembled.
The layers were imported into EnRoute in separate files and then using the trace function to create the vector files for the gate. EnRoute's tracing function is the best I have ever used and extremely fast.
Since the gate halves were larger than the steel sheets we were using he then had to decide where the cut lines would be so the pieces were easiest to weld together. Each of the five layers was done in this fashion.