The interfacing looks like this. This brand comes with pieces of paper on both sides. The side that is stickier I stuck to the wrong side of the fabric. Then the protective paper, and the final layer is the pattern, upside down. So I cut four layers at once.
Taking the paper layer off the red fabric, I ironed the "S" right on top of the yellow.
The way I cut out the red and yellow did not exactly match, but it didn't matter because when I zig-zagged around the edges the yellow that peeked out dissappeared. I guess you wouldn't really have to zig-zag around the edges, but it keeps all the little frays in place and gives the symbol a more professional look.
It was a quick sew, but not quick enough for Stuart as he stood by anxiously awaiting its finish. Then he wore it all day except when he was eating...as requested by me. (I don't want that costume stained before Halloween!) Now, to get some matching velcro and I'll use the same cape as last year-it's still in pretty good condition.