Several members like [USER=49319]SSGLordBert[/USER] have 3D printed neck seals in flexible filament like TPU.
Others like [USER=493]marinesniper[/USER] sculpted and then molded and cast neck seals in flexible rubber.
[URL unfurl="true"]https://www.405th.com/forums/threads/neck-seal.54688/[/URL]
Others have utilized the Evil Ted pattern:
[URL unfurl="true"]https://www.405th.com/forums/threads/foam-h5-neck-seal.49921/[/URL]
Others custom make their patterns using "Duct Tape Dummy" method:
[URL unfurl="true"]https://www.405th.com/forums/threads/halo-reach-near-game-accurate-neck-seal.45232/[/URL]
[URL unfurl="true"]https://www.405th.com/forums/threads/pipninjas-spartan-neck-seal.53536/[/URL]
[URL unfurl="true"]https://www.405th.com/forums/threads/halo-reach-near-game-accurate-neck-seal.45232/[/URL]
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.
[URL unfurl="true"]https://www.405th.com/forums/threads/easy-hex-pattern-neck-seal-based-on-blue-realm-pattern.39102/[/URL]