Once the tops?called the brush or the hurl?are cut from the stalks, the seeds need to be combed out. In the early days, and with a small crop like this, an actual comb does the job. There were machines invented to use for large production, called seed scrapers. After the seeds are gone, you can see the fibers that will make up the broom. When fresh they have a green color, which was very desirable; often sulphur was used to keep or enhance the green.