How to Sew a Flat Smooth Hem

Sewing machine with needle
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While the key to a flat hem is to always have a 2" hem so the garment will hang nicely, this does not work for skirts. This is because, on a skirt, the hem facing (the inside of the hem) is much wider than the area where the hem is sewn in place. The outer edge gets wider the further out you go, so the deeper you try to make the hem, the more you have that will need to be eased in, in order for that hem to lay flat. 

If the fabric has plenty of body on its own, a rolled hem may be sufficient. A fabric such as felt or ​Polar Fleece will not need any hemming. A woven fabric will need some kind of hem. The looser the fabric weave, the easier it will be to ease in the fabric of the hem to make it fit without any tucks or gathers.

A simple sewing process makes it possible to ease in the fabric threads to make the hem fit in the desired location. Unless you are trying to hem a perfectly straight skirt, you will have to ease the hem facing in, in order for the hem to lie flat.

What You'll Need

Equipment / Tools

  • Sewing machine
  • Straight pins
  • Fabric marking tools (optional)

Materials

  • Thread
  • Needle
  • Hem tape (optional)

Instructions

  1. Mark the Hem

    Decide the hem length and mark where the hem will be folded. Mark enough locations to have a continuous line for the fold. This can be marked with straight pins or fabric marking tools.

  2. Pin Hem in Place

    Fold the hem upward on the marked line, pinning the hem in place as you go but leaving the upper edge of the hem facing unattached.

    A hem with many curves, such as the hem that is short in the front and long in the back on a gown, will need a narrow rolled hem. Adding a hem lace or a serged edge would be visible from the front of the gown. Turning under the fabric and creating a hem that is 1/2" wide on a silky fabric will help the edge maintain its shape and will visually blend in with the fabric from the front short area of the hem when the gown moves.

    A circular hem such as poodle skirt will also be a shallow hem facing to allow for the amount that will need to be eased in. In most cases, an inch is a sufficient hem. A serged edge or hem lace can also be used to add to the hem length but you will want to ease in the fabric before adding the hem tape.

    A straight hem can easily be a 2" hem and will usually help the garment hang properly. In some cases, hem weights are also added to help the garment hang properly. A hem weight is hidden inside the hem and is not visible.

  3. Finish and Create Hem

    Once you've decided on the amount of hem facing you are going to leave, mark that amount on the inside hem fabric, marking from the fold of the hem. Join the markings to have a distinct line to evenly trim away any excess hem fabric.

    Trim away the extra fabric. Decide how to finish the raw edge of the fabric. In many cases, the same type of seam finish used throughout the item can also be used to finish the raw edge of the hem. Knowing your options allows you to have the best possible results.

  4. If the Edge is Turned Under

    • Sew a line of machine basting stitches 1/4" from the raw edge.
    • Press under the raw edge, to the wrong side of the fabric, folding the fabric directly on the machine basting line of stitches.
    • Pin or hand baste the hem in place 1/2" to 1" below the machine basting stitches.
    • Gently tug the machine basting stitches to ease the hem facing to fit the hem facing to the fabric, without any gathers forming
    • Press again to be sure the hem fits the fabric.
    • Stitch the hem in place.
  5. If Using Hem Tape

    Hem tape and hem lace can be found in fabric stores where bias tape is sold.

    • Sew a line of machine basting 1/8" to 1/4" from the raw edge of the fabric.
    • Pin or hand baste the hem in place 3/4" to 1" below the machine basting stitches.
    • Gently tug the machine basting stitches to ease the hem facing to fit the hem facing to the fabric, without any gathers or tucks forming.
    • When you are happy with the way the hem fits the main fabric, sew the hem tape to the raw edge using your machine basting as a guide so the easing stays in place with the hem tape or lace.
    • Press again, and ease using the stitching if you need to, to bring the hem in to fit the fabric.
    • Sew the hem in place at the top of the hem tape or lace.


    Why Use Hem Tape?

    • A fabric that needs a finished edge but is thick so that if you pressed under ​an edge, you would have a bump that is apt to press through the outside of the garment, is an ideal place to use hem tape. The hem tape, will secure the fabric edge but also provide a transition as the hem edge is attached.
    • ​If the amount of fabric you have is a little scarce, using a hem tape or lace will extend the amount of fabric for the hem facing.
    • A fabric that has very little capability of easing the fibers together can be eased in a bit more by using a hem tape that is also eased to fit in the desired area.
    • These tapes offer a smooth surface in an area that the fabric may not be smooth when it is rubbing against skin or nylons. Many loosely woven fabrics will not give a smooth edge even with the fabric turned under. Using a seam tape along the hem edge solves this problem.
  6. If the Hem Facing Edge Will Have a Zigzagged or Serged Edge


    • Sew a line of machine basting 1/8" to 1/4" from the raw edge of the fabric.
    • Pin or hand baste the hem in place 3/4" to 1" below the machine basting stitches.
    • Gently tug the machine basting stitches to ease the hem facing to fit the hem facing to the fabric, without any gathers forming.
    • When you are happy with the way the hem fits the main fabric, serge or zigzag the raw edge.
    • Press again.
    • Sew the hem in place.