Garment Construction and Sewing Techniques
Overview
Garment construction tests seams, stitches, machine control, pressing and component attachment. Marks are lost for skipped stitches, puckering and unfinished edges.
Seams and stitches
A plain seam joins two pieces right sides together, usually with 1–1.5 cm allowance, then edges are neatened. A French seam encloses raw edges and suits light fabrics. A flat-felled seam is strong and neat, used on jeans and shirts. Overlocking neatens and stretches with knits. Straight stitch is for seams, zigzag for stretch and neatening, blind hem for hems, and buttonhole stitch for openings. Match needle size and thread to fabric: fine needle for silk, medium for cotton, heavier for denim.
Machine control
The needle carries thread through fabric; the bobbin supplies the lower thread; the feed dog moves fabric; the presser foot holds it; the tension dial balances upper and lower thread. Correct tension makes loops meet inside the fabric. Stitch length around 2.5 mm suits medium cotton.
Worked example
For a cotton cushion seam: place right sides together, match raw edges and notches, use 1.5 cm seam allowance, stitch at 2.5 mm, backstitch at both ends, trim threads, press the seam open, then overlock or zigzag the edges. Reasoning: matching notches prevents twisting; pressing open distributes bulk; neatening stops fraying. On a curve, clip seam allowance at intervals instead of stretching the fabric.
Traps
Poor tension, wrong needle, no backstitching, trimming seam allowance before fitting, pressing by sliding the iron, and clipping through stitches are costly. Test on scrap first.