The basics of machine reverse appliqué are simple, provided you know the basics of using a sewing machine. In addition to the machine you will need embroidery scissors with a sharp point.
1) Use triple (straight) stitch
This prevents the cuts in the cloth from fraying. It is also a pain to unpick triple stitch. You can see it has taken a few tries to get the square mostly square. I’ve left the stitches in of the other lines rather than unpick them.
2) Choose two materials to start with, preferably with contrasting colours. My sampler top layer blue with a large rose pattern, the red bottom layer has a smaller floral pattern.
3) Sew a shape, any shape. It is important that there be no gaps in the sewing. Again stops the cloth fraying.
4) Inside the shape try and separate the layers. Use the point of the embroidery scissors to start a cut in the top layer. Cut around the edge of the shape. Congratulations, you have finished your first piece of reverse appliqué. Sometimes you will cut through the second layer, which can be patched from the back.
Design for reverse appliqué is done by combining shapes together until you have a design. You don’t have to cut every sewn shape out. I’ve used a grid on my sampler to make a check pattern.
Divisions for example is based on a grid overlayed with a right angled triangle. The one design difficulty with reverse appliqué is that to cut out a straight line you need to sew a narrow rectangle. Truly fine lines need to be embroidered.