Basic Cutting Methods
One-Piece Folding Cutting Method
Fabric Preparation: Select elastic knitted cotton fabric (1.5 meters wide), fold it completely in half lengthwise, ensuring the edges are aligned and wrinkle-free.
Outline Drawing: Draw the outer outline of the underwear directly on the folded fabric (front piece higher, back piece lower, back piece 3-5 cm longer than the front piece), and cut two symmetrical pieces in one go.
Crotch Treatment: Cut a U-shaped crotch piece separately (12-15 cm wide, 18-20 cm long), mark the center line as the positioning point, and leave a 1-2 cm allowance when joining it to the front crotch piece to enhance the fit.
Upcycling Method
Use a well-fitting old pair of underwear as a template, lay it flat on new fabric and trace the outline, leaving a 1.5 cm seam allowance. Suitable for quickly replicating patterns and reducing size errors.
Geometric Cutting Methods
Rectangular Method:Calculate the horizontal length based on half the hip circumference plus a 6cm allowance. Measure the vertical length from the waist to the upper thigh (25-30cm). Suitable for standard body types.
Trapezoidal Method:Upper hem = waist circumference/4, lower hem = hip circumference/4. Height is the length from the waist to the crotch. Fits the hip curve better.
Key Detail Treatment
Crotch Three-Dimensional Structure:Men's underwear requires added three-dimensional space in the crotch area of the front panel. This can be achieved through darts or a front center slit design. Double-layered crotch fabric (thin cotton lining) reduces the thickness of the seams.
Elastic Band and Hemming:
Waistband:The elastic band length is 10cm shorter than the net waist circumference (e.g., 66cm for a 76cm waist). Fold inwards or bind the edges.
Legs:Hemmed with elastic binding strips or directly rolled up and sewn, with a width controlled within 0.5cm. Sewing Process
Crotch Seam: A "sandwich stitching" method is used, where two main fabric pieces sandwich the crotch fabric, followed by a U-shaped stitch and overlock for reinforcement.
Side Seam Treatment: A seamless, one-piece design reduces friction, or the seam allowance is pressed towards the back piece after sewing.
Fabric and Tool Selection
Fabric: Preferably 95% or higher cotton knit fabric (weight 180-220g/㎡), with 30%-40% horizontal elasticity and 15%-20% vertical elasticity. Pre-shrink before cutting (soak at 40℃ for 30 minutes).
Tools: Sharp fabric cutters, Z-stitch sewing machine, elastic binding tape (2cm wide). If an overlock machine is unavailable, hand sewing with parallel stitches is acceptable.