Not all designs will produce the sparkling effect. The design cannot be too dense when using an embroidery design. I found a lovely butterfly design from Dream West Embroidery. It stitched out nicely and shimmers away! Hoop your fabric as normal, place a piece of Mylar on top (I tape mine to keep in place until the stitches hold it), and begin. Before long you have a gorgeous and shimmery design! Not sure where my butterfly is going, but it will look great!
There are many who would love this shimmery effect but don't have an embroidery machine. I turned next to my Singer Curvy to see what would happen. I needed enough stitching to hold the Mylar, without begin too dense. For my heart I went REAL simple. I just choose some of the decorative stitches and began filling in the heart. When you are finished, the excess Mylar just tears away. Get those tight stubborn spots with your snippets. After sewing, you can still cut through the design without damaging anything. I wanted my heart a tad smaller and more shapely, so I cut to the size I wanted. (not very creative today and will certainly try another design on the sewing machine tomorrow - maybe a Sunbonnet Sue).
Thanks to the pressure adjustment on the Curvy I was able to quickly applique the heart to a piece of imitation leather using the blanket stitch. Around the edge the feather stitch came in handy. This may turn into a pocket in one of my purses or totes. Also thinking it could be the pocket of a jean dress. That's another day!
The important bit for me was being able to use the Mylar with my sewing machine. Give it a try and you might be addicted!
Mylar is the opalescence tissue used in gift bags. You might find it with the wrapping paper in your local store. I will be searching some more out, but the tissue I got from Sharon arrived very quickly and was very economical. This is not the Mylar you think of in Mylar balloons.
The photos just don't show the true beauty of the designs. I will certainly be adding more of this to my sewing.