Here you can download a simple Celtic knot 2D design. The design is of rectangular shape and drawn using a grid in 2D CAD software.
Celtic knot patterns are very easy to draw with the help of grids, and on the Internet there is a lot of information about how to draw them. If you are really interested in drawing Celtic knot patterns, study the ways how it should be done; it would be also worthwhile to learn the basics of drawing in some free 2D CAD or vector software. Using the above software, these patterns can be drawn very quickly and accurately, and another great advantage is that if, for some reason, you are not satisfied with the pattern design, it can be modified in an instant. When you become familiar with the drawing method, you will see that there are variations of these patterns and that they can be drawn in any shape. In the end, not only will you be able to draw Celtic knot patterns to fill some space, but also know how to make frame borders of various shapes and sizes from them!