large applique?
 

I have a large applique piece (about 4'x4') that I will put as a center focus on a quilt. however, I have never dealt with such large applique. I cannot do raw edge, because I need the edges to fold under 1/4". what is the best method to use for this? and the edges are not straight, they are irregular and with curves. Thank you

Could you try using interfacing, iron-on or not (sticky side to main side of fabric), stitch around the edge, trim - then put a cut in the interfacing and turn inside out. You will have the correct side out and can either iron your applique to the block or just pin and sew.

If you will be doing hand appliqué, you might try Jeana Kimball’s backbasting needle turn method. This method allows you to turn the edge on just a small section at a time. With that large of an appliqué, after marking the design in reverse on the back, I would probably glue baste the appliqué on the front to the background to make sure everything lays flat, even if that means sometimes have to fight the glue when trying to turn the edge. Best of luck.

Is this something you definitely want to machine applique? If you're thinking of doing it by hand I would encourage you to look at Hawaiian quilting videos on YouTube. The method would be the same. Not for the cutting out, but for the placement, basting, and stitching.

When using the fusible interfacing, when you trim curved edges, it will work much better if you use pinking scissors. Then when it is turned right side out the pinked edges give you a better edge to work with.