I trying to find some wide pieces of sil-nylon (or other proofed nylon) to have a go at my first tarp, the biggest widths only seem to be around 60-62".

Is there somewhere where I can get more like 11-12ft ?

I'm tempted to have a go with the narrower stuff anyway just as a practice run, for a real user though I'd like something without any seams to seal, especially directly over my head