Altering jeans is feasible, offering a way to achieve a custom fit. Denim is a durable, heavy twill-woven cotton fabric, making it exceptionally versatile for modification. Its inherent strength means it can withstand significant reconstruction and tailoring. Successfully tailoring jeans necessitates specific tools and techniques to manage the fabric’s substantial density and thickness. This guide presents the necessary preparation and detailed steps to achieve professional results when adjusting the length and fit of denim garments.
Preparation and Essential Tools
Working with multiple layers of thick denim requires specialized equipment to ensure clean stitching and prevent damage. A heavy-duty sewing machine is necessary, as standard home machines often lack the motor strength to power the needle through dense seams. The pressure foot must maintain consistent contact over uneven terrain, particularly where four or more layers of denim overlap.
The needle must be a specialized denim or jeans needle, typically sized 90/14 or 100/16, featuring a sharp point and a reinforced shaft. This design minimizes deflection and breakage when encountering the fabric’s tightly woven fibers. Strong, durable thread, such as polyester or a cotton-wrapped polyester blend, should be used, offering the necessary tensile strength to withstand the stresses of wear and washing.
Before cutting, precise marking tools like tailor’s chalk and accurate measuring devices are mandatory. High-quality, heavy-duty shears are also required to cleanly cut through the thick fabric layers without fraying or damaging the denim’s edge.
Adjusting Length Hemming Techniques
Standard Straight Hem
Hemming is the most frequent alteration performed on jeans and involves establishing a new, precise length before securing the raw edge. To begin a standard straight hem, mark the new length while the jeans are worn, then add a 1.5 to 2-inch seam allowance below this line before cutting the excess fabric. The raw edge is then folded inward twice—first by half an inch, then by the remaining allowance—to fully enclose the cut fibers within the fold.
The main challenge is managing the thickness where the leg’s side seams meet the folded hemline, which often contains six or more layers of denim. These areas can stall or break a needle. To reduce bulk, carefully taper or shave down the seam allowance inside the hem fold at these junctions before stitching. Stitching is performed close to the inner folded edge using a high-tension straight stitch.
The Original Hem Technique
The “Original Hem” preserves the jeans’ existing factory-finished hemline, including specialized chain stitching and natural fading. This method involves cutting the excess length above the original hem and reattaching the preserved hem piece to the newly shortened leg opening. This process requires meticulously aligning the side seams and stitching the two pieces together with a strong, straight stitch just above the original fold line.
The final step is to press the new seam allowance upward and stitch it down onto the main body of the jeans, effectively hiding the new seam inside the leg. This technique is preferred for high-quality denim as it maintains the garment’s authentic wash and wear patterns at the cuff.
Modifying Fit Waist and Width Changes
Tapering Leg Width
Adjusting the circumference of jeans, whether at the waist or the leg, involves deconstructing and reconstructing major structural seams. Tapering the leg width is accomplished by taking in excess fabric along the inseam, the outseam, or both, depending on the desired shape change. The new stitch line must transition smoothly from the original seam, typically starting around the mid-thigh, and gradually angle toward the desired new width at the knee or ankle.
A smooth curve must be maintained through the new stitch line to prevent the fabric from bunching or twisting once worn. This modification requires careful mirroring on both legs to ensure symmetry and balance in the garment’s drape. After stitching, the original seam allowance is trimmed, and the new seam is pressed open or to one side to ensure a flat finish.
Modifying Waist Circumference
Modifying the waist circumference, usually to reduce the size, requires working exclusively on the back center seam. This alteration is complex because the waistband must first be completely detached from the back yoke. The center back seam is then taken in by the calculated amount, creating a new V-shaped seam that narrows the overall width.
Once the back seam is stitched and pressed, the waistband is trimmed by the same amount and carefully reattached to the yoke and upper edge of the garment. Precision is paramount during reattachment to ensure the waistband lies perfectly flat, preventing puckering or misalignment of the belt loops.
Advanced Techniques and Material Challenges
Specific denim compositions require unique handling to maintain the fabric’s intended characteristics after alteration. Jeans containing elastane or spandex for stretch require a slight zigzag stitch, rather than a rigid straight stitch, for any seams that will experience tension. This minor lateral movement in the stitch allows the seam to stretch alongside the fabric, preventing the thread from snapping when the garment is worn.
Selvedge denim, recognizable by its tightly woven, clean edges, presents a unique consideration when adjusting the outseam. If the outseam is altered, the distinctive finished edge must be maintained and remain visible on the exterior of the leg opening. This requires careful planning to either adjust the inseam only or to reconstruct the outseam so the selvedge edge is properly aligned and secured.
The final step for any alteration is the thorough pressing of all new seams. Applying substantial heat and pressure flattens the thick denim layers, permanently setting the stitches and integrating the alteration into the garment structure. This process removes the visible signs of reconstruction and contributes significantly to achieving a professionally tailored appearance.