Recently I purchased a stole at a vintage shop. I had to have it, just to get an example of this extraordinary trim, which I then had to figure out how to make. This post presents the results. Don't miss other Threads techniques like this by purchasing a print subscription which comes with FREE access to our tablet editions.
Here's a detail, that shows how this sweet little trim can be used to good effect.
When explaining this trim, as well as other kinds of ribbon work, I will refer to the unit of measure as "ribbon width". I learned about this method of measurement from Candice Kling's excellent book The Artful Ribbon.
Using the width of the ribbon as the increment of measure, makes any work easily scalable, either larger or smaller. The trim on the inside of this stole was 3/8" finished width at its widest point.
Since you will lose 25% of the ribbon length when making this trim, make sure to cut your ribbon length 125% of the finished length you need.