Here are svg files for two versions of a celtic knot border. The border file is for using as a border or welding onto your projects. The insert file is for cutting the knot border out of your projects, or it can be welded together to make a longer border. :)
The download is a zipped folder with svg files for use in either version of SCAL. These files are for personal use only. Feel free to link to this post, but the files are not to be shared or distributed in any way.
Download the files from here.