Waterproof thread?

Question

where can i find waterproof thread DOES IT ACTUALLY EXIST!!??

Answer 1

Mono filament thread or Clear Quilters Thread ;)))

Answer 2

I'm not sure exactly what you want, but would fishing line work? I've mended shirts and stuff with fishing line before. What do you mean by waterproof though? Do you want it to seal something so it is watertight, or do you want it to hold while wet?