Have you ever had the experience of getting a pattern that doesn’t have the end of the dart marked? Or, have you mistakenly failed to mark the end point of the dart and only discover it well past the point of recovery? This has happened to me several times. One is left scrambling trying to figure out the angle and location of the end of the dart. If this has happened to you, the solution is simple. Here’s the sample pattern in question. The dart legs are marked with notches but the end point is missing (below).

The technical name for the process we will use to repair this situation is triangulation. You will need the sample garment, a ruler, pencil and a compass. If you don’t have a sample garment like I have, you will need to guesstimate the desired length of the dart. You can measure a form or a live body to estimate length starting at the side seam and comparing it to desired end point.

Below I’m measuring the length of the dart with a ruler. I suppose you can also use a tape measure but I couldn’t use a tape measure and take a picture at the same time. This dart is 5″ long.

The next step (below) is to mark off the seam allowance at the notches indicating dart position at the side seam. Note I’ve created cross marks, extending the dart leg notches to meet at the seam line.

Next, extend your compass to the desired dart length (below).

Starting at one notch (the cross mark intersection of dart and seam allowance), use the compass and draw a line, maybe three or four inches. It doesn’t matter really, you will erase the excess (below).

Below I’m triangulating from the second notch position, drawing a second line. The object is to intersect the two lines drawn by the compass.

Below you can see the intersection of the two triangulated lines. Sorry those lines aren’t more pronounced. I prefer to draft with 4H pencils because the lines don’t ghost once erased.

And lastly, you can see the end point more clearly. To make the dart end official, I’ve backed off the end point of the dart 1/2″ to mark the drill hole. It’s standard in the industry to sew 3/8″ or 1/2″ past the punch or drill hole. I’ve circled the position of the drill hole. All that’s left is punching a hole and erasing all of those lines so it’s not so messy looking.