4-Cord Celtic Knotwork

The larger knotwork patterns are created using four strands or cords.

The following instructions are for drawing celtic knots based on a 4-cord design, including knots 3 through 8 as identified by J. Romilly Allen. Instructions for drawing 3-cord knots are on a separate page.

Step One: Mark off a section of graph paper two units high and twelve units wide. (We have defined one unit to be four small squares on the graph paper in the figures.) Put a dot at the one-quarter and three-quarter point along the center line of each square. That is to say, draw a horizontal line through the center of each square. Then, put two dots on the line: one one-quarter of the way across the square and the other three-quarters of the way across. (Do all these steps very lightly in pencil!)
	Step Two: Use (45 degree) diagonal lines to connect the dots on opposite sides of the rectangle.
Step Three: Extend every other set of diagonal lines to form points above and below the initial lines. It is important that you extend the diagonals as shown, not the ones in between. If you number the top row of dots 1, 2, 3, 4... from left to right, your peaks should be between 1 and 2, 3 and 4, etc. Not between 2 and 3, 4 and 5, etc.
	Step Four: Connect the points with arches. Note that the arches that move into the corners are shaped with points. Also, make sure your arches are of constant width.
Step Five: Erase the dots.
	Step Six: Erase one cord's lines from each intersection to create the illusion that one cord goes over the other. Remember that you must alternate between "overs" and "unders" to achieve the weaving effect.
Step Seven: Clean up any stray marks. This stage is known as the knotwork plait.
	Step Eight: Break the plait at appropriate intersections by erasing the lines where they cross. Then, reattach the lines so that each cord goes back on itself instead of continuing along the plait. Fill in the cords with the color of your choice and the background with a dark or neutral color.

That's basically how to draw celtic knotwork. 3-cord knotwork is constructed using very similar steps, but the grid is slightly smaller.