I finished the bunting! Yay! It turned out really cute. I used 5/8-inch polyester ribbon and sewed each triangle onto the ribbon. I just estimated the spacing so its not always entirely even but that helps its sweet folksy look. I decided to divide the triangles into three strips (lines?) of bunting so that it would be easier to hang them in the yard and they’d be more flexible for future decorating. I ended up with 33 triangles (11 of each color) so each separate bunting had 11 triangles and measures about 15 feet.
The open sides (tops) of the triangles frayed during the dyeing and washing process, so my original thought was to fold them in with the ribbon between the sides and sew it that way, but I ended up leaving the raw edges turned up and just zigzag stitching with the ribbon pressed inside – again, it adds to the folksy look.