Material for making dry bag (seams)

[Tbuckus]

I have a KUIU game dry bag that has some thin plastic that goes along and on the sewn edge perimeter. It looks like a good way to beef up the sewn edges.
Any idea what they use?
And if so, who would sell it?

 

[WoodBow]

Are you wanting to make dry bags or just looking for a way to strengthen seams on other projects? Grosgrain is the standard material used to reinforce and dress up interior seams on packs and such. It is not the plastic like material you are talking about though.

 

[pods8 (Rugged Stitching)]

What woodbow said. If going for waterproof it's seam tape (I have never used any personally).