I'm making my first tarp...I have some coated ripstop from WM, in 66" width.

Looking at some of the patterns out there, I've noticed that there aren't any tarps at 66" wide. So maybe that width doesn't work...or does it? (ENO Double).

If I need to go wider than 66", say up to 99", I was thinking of taking a second piece of the 66", cut down the middle, then sewing the resulting 33" piece to the edge of the first piece. This would result in an offset seam, as I will put the tie outs at the middle of the width (54.5"). In other words, when pitched, the tarp will have a seam about 21 inches to the side of the ridge.

Has anyone had any experience with this type of setup? Will it screw up the pitch when it's set up?

Thanks for any help or advice you can give.