When creating a catenary-cut flat-felled seam, did you have any problem with the finished seam not stretching flat under tension?
Sometimes yes, but not to the extent that it interferes with seam sealing. I center the seam like you do as described in a previous post.
There are a couple of things you can try to help keep the seam flat.
1. After the first stitch line, pin the folded seam down. You don’t have to pin in advance from end to end, but at least several pins and a couple of feet ahead of the presser foot. If the fabric does stretch and bunch, you’ll see it and can make adjustments.
2. Use a wide presser foot on the sewing machine and adjust it side-to-side for best coverage of the seam.
3. Sew the seam under a bit of tension.
4. Use a narrower seam like Jerry does.
When attaching the netting skirt to the underside of the tarp, what was your technique to mark a symetric seam line (the white markers) that fit perfectly with the perimeter length of the mesh?
I’ve been using CAD software and have full sized patterns printed at the (expensive) local print shop. The patterns have alignment marks on the corresponding pieces.
Here is an alignment mark on the mesh wall pattern. Chalk doesn’t work well on mesh, so I snip the fabric to mark it
You can see an alignment snip mark through the mesh hem here:
Fly pattern cut to expose alignment template:
Alignment marks transferred to fly fabric:
Hope this helps,