Top stitched french seam
An easy seam for joining fabric when making tents and tarps.
YAMA recommends do-it-yourselfers use the top stitched french seam for ridgelines and seams between different panels of a tarp.
Watch a video of the seam construction process: http://youtu.be/LN5aOHmCrDM
NOTE: YAMA does not use this process in production. Instead, industrial double needle machines are used to construct seams in a more efficient manner.
How to sew it:
With right sides together, sew a basting stitch about 1/4” off the edge of the fabric.
Turn the fabric so the wrong sides are together and so the fold lies along your basting stitch, then stitch about 1/4” off the fold.
Spread the fabric so the right sides are facing up. Then fold over the flap and stitch close to the edge to complete the seam.