Terry, Sounds like a flat lock stitch. Depending on which side you look at the seam one is a "ladder" and the other is more of a criss-cross type stitch.
I have done some early quilts by taking panels and serging on straight borders. Several rounds of borders to make a throw size quilt.
I may have even done a serger "satin stitch" to finish the edges of some of those quilts. I know I quilted them by using decorative stitches over the seams with decorative threads. <G> the last I saw of some of those they were beginning to look well used. But they have held up for almost 10 years. <G>
Serging would be a good way to do a "casual" type quilt pattern, not a lot of intricate piecing, fairly large pieces, that is to be used as a "summer quilt". Summer quilts don't usually have batting and are just tacked to a backing. Often they are just "pillowcased" and turned to back them. Simple stitching helps hold the back and top together.
Pati, in Phx
Originally Posted by Terryl
I wish I could remember which stitch we used when I made my quilt on the serger, the class I took was for a wall hanging, but me, being me, I made a kingsized quilt, just tripled the pattern we were using, anyway seems to me we serged the fabric wrong sides together, then when we opened the blocks out they were flat but you could see the stitches, sort of like decorative stitches. I didn't notice any extra bulk when it was quilted. I'm in the process of moving now so once we get settled (if I don't forget) maybe I'll take the quilt out and see if I can identify which stitch we used.