This is a great answer to a question about floating selvedges. When you are weaving a piece on a 4+ shaft loom it is usually a good idea to have a floating selvedge on either side (left and right) of your piece. These threads help you to ensure that each pick (weft thread) is firmly embedded at the edges. If you are doing a pattern where you go under 3 threads each time, or over 3 threads, or more on a very complex loom, then there is the possibility that you will have a couple of warp threads just running up the side of your piece for 2-3 rows or more depending on your pattern. This would look stupid, I know from experience, and get snagged really easily. By putting the selvedges in you keep the edges looking tidy. To learn more about selvedges I recommend checking out the video mentioned in this article.