Here are two threads on how other Members have made their own neck seals. One utilized the Evil Ted pattern, and the other is a custom one based on the "Duct Tape Dummy" method Alexander talked about.
Foam h5 neck seal. Started with Evil Ted Smith's foam neck pattern.
www.405th.com
Hey guys! So one thing that my suit has been lacking (and something my next suit will need) is a decent neck seal. I had originally made a sort of tube sock that slipped over my head and covered my neck, but it didn't look all that great, and was a pain when removing or putting on my helmet. I'm...
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And an older thread where you can see the pattern used, and might be able to transfer it from the image shown to your own paper.
I am no good at sewing, so I decided to try something a bit different for my neck seal. I bought some 2mm Aero-Mat to use as material since it already has a hex pattern. http://www.acpsales.com/Aero-Mat.html I used the neck seal pattern from Blue Realm Studios as a template...
www.405th.com