Hello, I'm just starting. I want to create a mold for a helmet. I'm in the prosses of using Pepakura to print out what I want. But I'm running into a problem I want it to the armor to fit but I don't know how to size it? I don't what to print it output it all together just to find out it won't fit. Is there a way around this? Or do I have to make adjustments as I build it?