WHAT IS IT?
Understitching is a row of stitching on the inside edge of a garment, usually a facing, sewn to keep the seam rolled to the inside of the garment. Understitching is never visible from the right side of the garment. Unlike basting, understitching is permanent. Understitching seems like a step you could skip, and just press the garment instead, but it makes a world of difference to the crispness of your edges.
Understitching on Saltspring Dress
Understitching on Cambie Dress
WHEN DO YOU USE IT?
Understitch after sewing the facing to the garment but before pressing the facing to the underside. Any garment that has facings can be understitched. Usually the pattern instructions will tell you when to understitch. But if they don’t, feel free to add it! (Read to the end of the pattern instructions before adding it in to make sure it doesn’t happen later in the construction.)
Tips + Notes
- Understitch linings as well as facings if they start to roll to the right side.
- You can also understitch by hand and thereby get into smaller areas like corners that the sewing machine can’t reach. Thread a handsewing needle with a double thread, and sew tiny prickstitches (page link) to secure the facing to the seam allowance. It’s time-consuming but adds a couture finish to gowns and formal wear.
HOW TO UNDERSTITCH A FACING
Grade your seam allowances (see trimming page link). Doing so helps reduce the bulk of your facing seam line.
Clip inner curves so the seam will lie flat by making snips into the seam allowance about ½” (1.3cm) apart. Make more snips into very curved areas and less snips into less curved areas. Be careful not to snip into your stitching line. Once clipped, the curve can now be stretched into a straight line! You’ve made your seam more flexible. This is an important step, as otherwise it will be harder to understitch the facing.
Arrange your piece so that the facing is on top. Open up the seam line and stretch the seam as much as you can (gently!) with your fingers. You’ll notice I didn’t press the seam open with an iron. I find you get better results by stretching and understitching and then pressing the facing. This way there’s no crease mark when you understitch.
Insert the needle into the facing, very close to the seam line. You want to keep this stitching very close to the edge, as close as you can maintain, while not crossing over onto the bodice front fabric. If you can manage to get at least 1⁄8″ (3mm) away from the fold, that will work. Lower your presser foot and begin stitching slowly as you stretch the seam open with your fingers.
Continue along the seam line until you get to the end. Backstitch and trim threads. Now look at how nicely your facing rolls to the inside of your garment. You’ve made it want to stay in the right place. Pressing the facing will be so easy since you’ve created this lovely natural curve.
Source : The Sewtionary An A to Z Guide to 101 Sewing Techniques + Definitions
About the Author : Tasia ST. Germaine