Very helpful information here. Thanks for posting.

I usually use spray starch on both sides of the base fabric. I also loosen the upper tension and check the settings (stitch length, width, and tension) on a sample first. You can use a stabilizer on the underside and I do on intricate applique but a lot of the time the spray starch does the trick.

Although I use Heat and Bond Lite, I use a tear-a-way stabilizer when using a satin stitch. For years, I've had no problems by using this technique.

The problem you decribe is what keeps many from using the satin stitch. Chances are that nothing is going to smooth it out now, how much did you do and can you pick it out?
With a satin stitch you need to loosen your tension slightly. Still need to use sablizer even if you use heat and bond because the outside edge of the stitch is hitting plain unbacked fabric hense the ripple. I like heat and bond LITE or steam a seam for most fused projects. always test on scraps.

I like to use steam a seam or heat bond lite; you can find them both at Joanns. The steam a seam is great because one side is a little sticky so it holds your applique until you iron it in place; keeps the pins out of the way and it can be repositoned until you get it where you need. I like both of these products because they leave your finished product soft where some of them leave it stiff. You should always to a test sample on scrap fabric of the same type before doing the project just so you know your stitch is right. Then when you know your stitch is right, write down the settings so that if you have to come back to it late or your power goes out you know what the settings were and it'll save you time

Tanya, how do you get at the under side of your applique if it's stitched down? Do you have to cut away the base fabric? I use Wonder Under or Heat n Bond light. I use tissue paper underneath if the fabric seems light. I don't want anything heavier because what inside the satin stitches stays there. My latest applique was hearts, so there were long diagonal lines of stitching.

Sometimes when you are satin stitching on an applique the pressure on the presser foot needs to be lightened up a little, and it always helps if you have a satin stitch foot. (They have a cut out depression on the bottom of the foot that allows the stitches to slide under easily.) Also if you pack your satin stitches too tightly it will cause buckling, so the thing to do is a test sample first and use JUST ENOUGH stitches to get the coverage.:)

Thank you for lots of good ideas to try.

Irishrose, I don't need to do anything to the back of my applique. I leave the Wonder Under paper in place until I am ready to put the applique onto another piece of fabric. Usually I have appliqued it onto a block and the block is what has the Wonder Under applied to it. If I am going to applique that block to a larger piece of fabric, then I peel the paper off the Wonder Under and press it down. If the block is totally finished and ready to sew into the quilt top, I leave the paper alone. When I sandwich the quilt then I peel the paper off and press it onto the batting.The wonder Under is so light weight that it is hardly more than a stiff starch or a spray on basting. I find it gives a wonderful feel to the fabric and makes it much easier to work with. I hope this made sense to you. Some of the appliques in my current quilt have several layers of fabric and therefore several layers of Wonder Under, but I'm not cutting the back fabric out of any of them. I may add extra batting to some of them for a more heightened raised effect . Since there won't be any quilting through the actual appliques themselves, the additional fabric thickness will have no effect on that.