Draw a Triquetra with Illustrator

basic triquetra

­­The Triquetra is an ancient symbol and makes an interesting design to create in Illustrator. It’s not hard to draw if you know how. Let’s take a look at how I made this.

I wanted to draw this symbol but I couldn’t find anything specific to doing so in Illustrator. I found several videos which show how to draw the triquetra with pencil and paper. I found one article which explains how to draw it with a compass and straight edge (on paper, of course). I decided to work out a process for Illustrator and boil the drawing down to simple steps. Once the shape is created you can modify the proportions and style it any way you like. You can change the band thickness and other attributes to suit after you have the basic process down. After the drawing is complete we will explore some styling ideas.

The design shown here includes the circle woven into the basic three-pointed design. You may easily exclude it if you only want the basic design. The steps in this post will get the geometry of the shape correct.

Let’s get to work:

Start by choosing the Polygon tool in the tool bar (it is under the rectangle tool).

Click and begin dragging out a shape (it is usually starts out with a hexagon).

While holding down the mouse button press the down arrow on the keyboard until you have a triangle shape.

Press and hold the Shift key while dragging the triangle a little and the base of the triangle snaps to the horizontal. Release the mouse button and then the Shift key.

triangleWith the triangle still selected, check that the width to height link is on. This protects the aspect ratio of the artwork while you resize.

link w and h

Select the value in the Width dimension on the Control Panel (top of the workspace).

width control

Set the width of the triangle to the desired size of your triquetra design (2 inches will work for this example [144pt or 50mm]). Press enter to set the new width. Illustrator draws equilateral triangles. This means that all of the sides are the same length. This sets up the exact geometry we need for the design.

With the triangle still selected click Object>Path>Add Anchor Points. If you look closely you will see that Illustrator adds an anchor point between every pair of points already on the shape. In this case three new points are added in the exact center of each side of the triangle. You have bisected all three sides.

We will need the geometric center (incenter) of the triangle later so let’s find it now.

Copy and paste a new triangle over the top of the existing triangle. Click Edit>Copy (CTRL/CMD + C) and then Edit>Past in Place (Shift + CTRL/CMD + V).

Click Object>Path>Average (ALT/OPT + CTRL/CMD +J). This reduces the top triangle to a point at the incenter.

Click View>Guides>Make Guides (CTRL/CMD +5). Hold the Shift key and click the triangle to select it and the guide. We don’t want that little guide point to get lost. To group them, click Object>Group (CTRL/CMD + G).

triangle with incenterStart drawing the circles that make up the design curves. Choose the Ellipse tool. Pick any of the anchor points in the center of a triangle side. Hover over the point until you see the word “anchor” displayed. Click and begin dragging an ellipse. While dragging, press Shift + ALT/OPT. The shift key causes Illustrator to make a circle and the ALT/OPT key causes the circle to be drawn from the center rather than a corner of the bounding box. This causes the circle to be exactly centered on the point in the middle of the triangle side.

Don’t worry about getting the circle the exact size you want at this point. Release the mouse button and then the keys.

Make sure that the width to height link is turned on.

link w and h

Go to the Width field in the Control Panel (top of the workspace) and set it to the same value you used for the width of the triangle (2 inches).

width control

The circle now passes through two corner points of the triangle.

triangle with circleRepeat the steps above to make two more circles at the other middle points or copy and paste the circle you made to the two other points. Hint: You can position the circle copies by dragging the center point to the middle of the triangle side. This ensures that the circle is positioned perfectly.

three circlesSelect all three circles. Copy and paste them over the top of the existing circles. Click Edit>Copy (CTRL/CMD + C) and then Edit>Past in Place (Shift + CTRL/CMD + V).

Deselect the circles and select one of them by clicking with the selection tool (do not drag select, if you do you will select both circles on that center point). Go back to the Width field in the Control Panel. Set the size of the circle to something smaller than the width of the triangle (1.7 inches looks good [122pt or 43mm]).

first of second circle setRepeat this on two other circles so that you have two concentric circles centered at three points.

outside circles doneStarting at the guide point in the center of the triangle, repeat the steps you used to make the first circle. From the center drag an ellipse and switch to a centered circle with Shift + ALT/OPT.

Set the size of the circle to 1.8 inches [130pt or 46mm] using the Width field in the Control Panel. Copy and paste this circle in place by clicking Edit>Copy (CTRL/CMD + C) and then Edit>Past in Place (Shift + CTRL/CMD + V). While the new copy of the circle is still selected set the size of the circle to 1.5 inches [108pt or 38mm].

construction completeNow that the construction is in place we need to modify it into the design. Before going on make a copy of the entire construction and set it aside. It will be much easier to experiment with the design later if you don’t have to start from scratch. I usually save copies of designs as I work so that I don’t have to start over if I make a mistake or I don’t like the way something comes out.

Select the triangle and delete it. After using it as a guide it is no longer needed. The triquetra design appears as though the bands weave over and under each other. In order to achieve this look we have to erase some line segments.

The lines in this shape pass by each other without anchor points at the intersections.  We need anchor points at the path intersections to remove segments for the crossovers. The paths then must be cut at the points. The paths segments must be removed and after all of that we have to join the paths together to make the strokes start and end where we need. It is tedious to do this manually so we’ll use the shape builder tool as a shortcut. Shape builder will do most of the work for us.

With the entire construction selected choose the Shape Builder tool.

 shape builder icon 1

Set a fill color for the tool so that you can see your progress as you move forward. Click in and area you want to create and drag across lines you want to remove. As the lines are removed it adds to the shape. When you release the mouse button Illustrator adds the fill color and removes the lines you crossed.

using shape builder Continue building on the shapes you want to keep. Use the image at the top of this post as a guide to build shapes in the design. Some of the paths have points inside the shapes you are defining. When this happens you may see a small bit of stroke left in the shape. To remove this, click in the shape and drag over the stroke. Shape builder will remove the portion of the stroke.

filling shapesAll of the shapes are defined.

extraneous lines removedThe last step leaves the design with a fill. You may use a color or pattern as desired. Set aside a copy of the filled design before continuing. Now this is a perfectly good design but I had something a little different in mind when I started drawing this design. I want to add a variable width profile to the strokes in this design. I want the strokes to be thin where they appear to be going behind the other elements and thicker everywhere else. This helps to trick the eye into seeing depth in the design. The problem with this treatment is that the areas of the design to be styled are closed shapes. The styled strokes will show up on the ends of the shapes and destroy the illusion. Sure we may be able to do something with clipping masks or layering copies of the shapes but I think it is just as easy to remove the lines at the ends of the shapes.

Remove the fill on the entire design (you did save a copy earlier right?).

remove fillDouble-click on one of the shapes to enter isolation mode. In isolation mode we can do the work needed without disturbing the other elements of the design. Notice that the other shapes of the design are grayed out.

enter isolation modeChoose the direct selection tool (A). Drag-select the points at one the end of the shape (make sure you get both corners. You can do one at a time if needed.). Click the cut path button on the control panel.

cut path button 1

Select and cut the points at the other end. Choose the selection tool (V). Select each end of the shape and delete. If there are small bits of line left over, make sure that you delete them all.

remove little bits in he cprners

When you are done with this shape, double-click on the artboard to exit isolation mode. Double-click another segment of the design to enter isolation mode. Continue with the shapes until they are all cut and exit isolation mode.

Select the entire design and choose a thicker stroke, 1mm or about 3pt is a good start. Go back to the control panel (top of the workspace) and select a variable width profile for the strokes.

variable width profilesI used the shape that looks like a Zeppelin (symmetrical, curved, wider in the middle and pointed on both ends). This shape is part of the default installation of CS6 and CS5.

style the strokes with a variable width profileIs this the only way to draw a triquetra? Absolutely not! The first one I drew I used a plugin to do all of the trimming to get the triquetra paths. It was a lot faster and easier. The Dynamic Sketch tool (part of the DrawScribe plugin) from Astute Graphics has a gesture trimming function. You just use a pen or mouse to cross the line back and forth three times and it ads anchor points and trims the line for you. It’s a lot faster (They don’t pay me to say this. I use the tool and it works for me.).

To make the bands of the design thicker reduce the size of the inner circles. You may also have to reduce the center circle to fit inside the curves. You have a vector version of the art so you can make it any size. You could replace the circle with a circle with an applied brush or blend giving you any number of choices of design (hearts, tree branches, flowers or anything you can imagine). If you do this you will need to mask where the circle goes “behind” the other design elements. You can do this by using copies of the filled shapes from earlier steps and trimming them shorter so they don’t interfere with the crossing lines.

 styled triquetra

This example uses gradient on stroke along with variable width profile strokes to produce a soft feathered look to the stroke ends. I drew small stroke-less shapes with a white fill to block the spirals where they “go under” the other bands.

Please leave comments on this or other posts. Suggestions are always welcome. What would you like to see on Rampant Pixel?

Leave a Reply

Your email address will not be published. Required fields are marked *