Some things we do with our sewing are meant to be seen, others are purposely meant not to be seen but are still important in the construction process. Understitching belongs in the latter category.

What is understitching?

It’s a line of straight stitching used to help keep facings in their place and tucked under the edge they’re finishing. You may have seen some necklines or armholes without understitching, and what do you see? A facing poking out and not staying in the place it was intended to be. Understitching goes through the facing layer and the seam allowances of the garment it’s attached to; so three layers, plus any applied interfacings. In most instances, understitching is done with a straight stitch. It shows only on the inside of the garment and not the outside, though its absence is often visible with roll-out edges.

In addition to armhole and neckline facing areas, understitching can be used on opening edges (front or back) and even when a garment is lined to the edge, like a skirt waistline opening. If your facings are a contrast fabric to the outer garment fabric, understitching is especially important to keep them hidden.

If there’s a collar, ruffle or trim band on the garment, understitching is imperative. The more layers you’re trying to control, the more important it is to understitch.

Understitching is not the same as topstitching. Though their functions can be the same—holding edges in place–topstitching is meant to be seen on the outside of the garment, understitching is visible only on the inside.

Understitching know-how

Most understitching is done by machine, though on heavy wools, fleeces, etc. it can be done by hand for better control. 

The straight stitch setting is all you need for understitching most garments, with about 10-12 stitches per inch. On thicker fabrics, you may opt for a zigzag or serpentine stitch for better control of the bulky layers. Remember, it doesn’t show, so you can even choose a decorative stitch if you prefer, just for a smile when you don the garment.

To create understitching, follow the pattern instructions to apply the facing or lining to the opening edge. After completion, trim and grade the seam allowances and clip any curves.  When grading, be sure to keep the longest seam allowance to the outside as the garment is worn and shortest toward the body. Stagger clips on the various layers to avoid “dimples” in the seam edge.   

Firmly press all the seam allowance layers toward the facing or lining. If the garment has a collar, this could be up to six layers, including the interfacings on the collar and facing.

Position the garment under the presser foot with the facing layer right side up and to the right your machine has an adjustable needle position, use it to fine-tune the needle placement near the seam. If your machine has an edgestitching foot, that can be helpful to keep the stitching straight, especially over bulky layers like cross seams. If your garment is lined to the edge, the understitching will be on the lining.

Understitching should catch all the seam allowances under the facing/lining, so keep your fingers underneath the stitching area to be sure layers don’t shift. Graded and clipped seam allowances sometimes decide to turn the opposite direction from how they were originally pressed, so be mindful of that and feel underneath as you sew.

On circular facings, like armholes and neckline openings, understitch all the way around. If your garment has a front or back opening, stitch as far as you can as you approach the corner. Then backstitch to anchor the stitch end.

Finishing touches  

Once the understitching is complete, turn the facing again to the wrong side and roll the garment edge ever so slightly to the wrong side next to the facing seam. Tack the finished facing edge to the adjacent garment seam allowancesat the shoulder, side seam, etc. to keep it in place.    {photo 4: Finished neckline with understitching}   

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~Linda Griepentrog is the owner of G Wiz Creative Services and she does writing, editing and designing for companies in the sewing, crafting and quilting industries. In addition, she escorts fabric shopping tours to Hong Kong. She lives at the Oregon Coast with her husband Keith, and three dogs, Yohnuh, Abby, and Lizzie. Contact her at gwizdesigns@aol.com.

Whether you’re new to sewing or a seasoned veteran with myriad skills, chances are good that you like to continue learning about your favorite hobby and knowing the vocab is essential.

While there are glossaries of common sewing terms, we wondered about the not-so-common words that might be good to know. If you missed Part 1, click here to learn those words, then learn these as well for your next game of Trivial Pursuit!

Besom Pocket

A besom pocket is inset into a garment (as opposed to being applied to the outside like a patch pocket). It is characterized by narrow piped edges along the pocket opening. Constructed similarly to a welt pocket, the narrow trim bands set it apart. The piped edges can be made from the same fabric as the garment, or from a contrast fabric or ribbon.

French Tack

A French tack is a grouping of threads used to hold two layers of fabric loosely together. Typically used to hold a lining in place at the hemline inside a garment, a French tack is about an inch long and the multiple thread strands are “overcast” together to hold them in place. French tacks are made by hand using a single thread to blanket stitch the initial strands together.

Hair Canvas

Traditional hair canvas is an interfacing fabric made from goat hair and/or wool, and it’s used in tailoring to give a crisp finish to lapels and collars. The real deal is quite costly, so manufacturers have come up with a substitute made from acrylic or polyester, cotton, rayon, wool and a small amount of hair. Hair canvas was originally only a sew-in product, but today there are now fusible versions as well. Because of its weight and character, hair canvas is best used on tailored wool garments.

Interlining

A layer of fabric behind the lining of a coat or jacket to add extra warmth. Often, it’s a lightweight wool, fleece or flannel depending on the amount of warmth needed.

Lambswool

A fluffy white woven fabric used in tailoring for sleeve heads, chest pieces and shoulder pads to add shaping and support.

Padstitching

Stitches used to hold one or more layers of interfacing to a tailored garment. Padstitching can also be used for garment shaping. The technique can be done by hand when it doesn’t show on the finished garment, or it can be done by machine where it’s visible upon completion.

Rouleau

Very thin fabric tubes used as button loops or for garment trim.

Sleeve Head

An added piece of woven fabric or interfacing placed at the cap of a sleeve to support the sleeve and maintain shaping. Sleeve heads are usually loosely hand stitched to the cap seam allowance. There’s no need to finish the edges of the sleeve head as it will be covered by the garment lining.

Tailor Tack

A tailor tack is a thread marking used to indicate a seam line or construction details, such as darts, match points, etc. Threads remain in the fabric until after stitching the marked item, then are removed. Tailor tacks can be made by machine, using a tailor tacking foot with a raised bar, or they can be made by hand using multiple thread strands.

When making tailor tacks by machine, use the special foot and sew a wide zigzag stitch along the designated design detail (dot, seamline, etc.) through the pattern and fabric layers. Clip the threads between the layers and leave the thread tufts in place until after final stitching is complete.

Underlining

Underlining is an extra layer of very lightweight fabric cut like the outer garment’s fashion fabric. The two layers are joined along the edges and treated as one during construction. Underlining is helpful for adding body to lightweight fabrics, and it helps retain shape on loosely woven fabrics. Often confused with interlining (see above).

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~Linda Griepentrog is the owner of G Wiz Creative Services and she does writing, editing and designing for companies in the sewing, crafting and quilting industries. In addition, she escorts fabric shopping tours to Hong Kong. She lives at the Oregon Coast with her husband Keith, and three dogs, Yohnuh, Abby, and Lizzie. Contact her at gwizdesigns@aol.com.