Here’s a simple Celtic knot you can make using only paper and scissors.
Download and print Style C templates. The file looks like this:
Cut out the two loops (cut out the doughnut holes in the middle, too).
Cut open the loops along the dotted line.
The lines across the loops indicate where another loop crosses over it.
Arrange the two loops to look like this:
Now that you’ve made a Celtic knot from paper, why not make one from fabric?