A dart is a tapered fold sewn into fabric, designed to remove excess material and introduce three-dimensional shaping to a flat garment. In jeans, darts are typically added to the back waist or seat area to eliminate the gap that often occurs when the wearer has a significant difference between their hip and waist measurements. This alteration allows the denim to conform closely to the body’s curves, resulting in a custom, snug fit that enhances the garment’s silhouette.
Preparing the Jeans and Pinning the Fit
The alteration process begins by turning the jeans inside out, which is the standard practice for marking and sewing on the wrong side of the fabric. The most common placement for darts is in the back, positioned symmetrically between the center back seam and the back pockets. This area provides the most effective location for taking in the waist without disrupting the side seams or belt loops.
To determine the exact amount of fabric to remove, the jeans should be tried on or placed on a dress form that matches the wearer’s shape. The excess fabric at the waistband is pinched and folded inward until the fit feels comfortable and smooth against the lower back. This pinched fold represents the depth of the dart at the waistline, which is the widest point of the alteration.
Once the desired fit is achieved, the pinched fabric is secured using straight pins inserted perpendicular to the fold line. Ensure the fold tapers smoothly down the seat area, ending where the excess fabric naturally disappears, typically a few inches below the waistband. This initial pinning establishes the general shape and depth of the required alteration before permanent markings are made.
Marking the Dart Lines
Translating the pinned fold into an accurate sewing guide requires the use of a temporary marking tool, such as tailor’s chalk or a fabric pen. The first step is to mark the center fold line of the pinched fabric, which serves as the axis of the dart. Next, the two sewing lines, known as the dart legs, must be drawn, connecting the marked width at the waistline to the dart’s endpoint, or apex.
The apex is the point where the dart terminates and must be drawn with a smooth, gradual taper to prevent puckering or dimpling on the outside of the jeans. For denim, the dart length typically ranges between three and five inches, depending on the amount of fabric being removed and the desired contour of the seat. If multiple darts are being used, it is necessary to measure and mark them symmetrically to ensure the waist reduction is evenly distributed across the back panel.
After the dart legs are clearly marked, the pins can be removed, and the fabric is folded along the center line, aligning the two marked dart legs precisely. This alignment is a fundamental step, as any misalignment will result in a crooked or uneven dart when sewn. The marked lines provide a clear, permanent guide for the sewing machine, ensuring the final alteration is accurate to the initial fitting.
Sewing and Securing the Darts
Before sewing, the machine should be set to a standard straight stitch, and a heavy-duty needle designed for denim should be used to penetrate the thick fabric layers. The stitching should begin at the wide end of the dart, right at the raw edge of the waistband, and proceed slowly along the marked dart leg line. Securing the stitch at the waistline is accomplished with a short backstitch, which locks the thread in place against the stress placed on the waistband.
As the stitching approaches the dart’s apex, the technique changes to ensure a smooth finish without a noticeable bump or dimple. Instead of using a backstitch at the point, the stitch length should be reduced for the final few stitches, or the machine should be allowed to sew directly off the edge of the folded fabric. Leaving long thread tails at the apex allows the threads to be manually tied off in a secure knot, which is the preferred method for reducing bulk at the dart tip.
Sewing slowly and maintaining a consistent line is important, especially as the stitch tapers to the apex. Even a slight deviation can cause a visible pucker on the outside of the garment. The goal is to create a gradual line of tension that molds the fabric without creating a sharp, unnatural point. Once the first dart is complete, the process is repeated for any subsequent darts, ensuring they are sewn with the same precision.
Finishing the Alteration
After the dart is sewn and the threads are secured, the final steps focus on neatening the seam allowance for durability and comfort. The excess fabric of the dart intake should be trimmed, leaving a seam allowance of approximately a half-inch. Because denim is prone to fraying, the raw edge of this trimmed allowance should be finished using a zigzag stitch or a serger to encase the loose fibers.
The finished dart must then be pressed to set the stitches and mold the fabric into its new shape. The dart intake is typically pressed flat and then directed toward the center back seam of the jeans. Applying heat and pressure helps to meld the stitches into the denim, creating a smooth, professional appearance on the exterior of the garment.
This pressing step ensures the dart lies flat against the body and does not create uncomfortable bulk when the jeans are worn. Once the pressing is complete, the jeans can be turned right-side out for a final inspection, confirming the alteration has successfully removed the excess fabric and created a tailored fit.