Bonnie that baby quilt is so pretty. The wavy line quilting looks great.

Bonnie, your baby quilt is so cute! :)
I have used wavy lines a lot. I usually quilt diagonally, from corner to corner. Starting with a lazy, wavy line down the center, I just echo it, trying to stay about the same distance away. After finishing one direction, I start at the opposite corner and do the same thing...making a big, diagonal, wavy 'x' accross the quilt. But, I've never done a quilt larger than about twin size this way.
Just to change it up a bit, I tried a QAYG, and quilted the blocks with diagonal, wavy lines, using a wide and long zig zag stitch. (my walking foot has a wide opening, so this works with it). I really liked the effect.
Now, I zig zag a lot of my fmq...stippling, meandering, echoing, even bubbles and vines are fun with zig zag stitches.

I've never heard of wavy line quilting but I like it and think I'll give it a try. TFS.

Ohhh! Thanks for asking this question, I have a sandwiched quilt that is waiting to be quilted and this is just what it needs. Thanks everyone who have posted photos, inspiring!

Thanks for posting those pictures, Jeanne, Nesie, Monika, and SewBiz. They are ALL so pretty and inspiring!

I use this technique A LOT instead of quilting in the ditch. This is how I do it: Using my walker foot (not necessary, but nice), I set my stitch selection to #25 on my computerized sewing machine (Brother SQ915). I change the stitch length from whatever it says it is to the maximum, which is 4 and 7. (If you want a smaller wavy line, make the numbers smaller -I used 2.5 and 4.5 on a small item I was quilting. If you can select this "wavy line" on your machine, just take a scrap piece of fabric and run it at the length it presets to, then experiment until you find what you like. Unless I absolutely HAVE TO quilt in the ditch, this is what I use instead. Oh, and the back looks just lovely with these wavy lines. HIGHLY RECOMMEND THIS TECHNIQUE!

Some machines have a serpentine stitch that does a wave, but the length and width are limited by the size the machine allows. I have used the painters tape method to define the width and then put a pin at regular intervals to make wider and longer waves. Then I use the bar that comes with the machine to set how far apart I want to echo the waves. I also have done the waves free hand deliberately not echoing the stitching to make it more interesting.