Wednesday, 24 November 2010

How to underline a garment

Underlining reinforces open weaves, prevents transparency and adds support. It is basted 1.3 cm (1/2 in.) wide to shell prior to sewing and acts as a single layer. Seam allowances of underlining are then optionally trimmed to the stitched line to prevent bulk. If you want extra support or to protect critical areas that will receive a lot of stress from being bent and sat on (elbows, rumps), hand baste underlining to the body of  shell parallel to the grain of fabric.

Broadcloth, muslin, fine cotton batiste, china silk, silk organza, cotton/silk batiste blend, cotton flannel or fusible interfacing can be used to underline a garment. If you use fusible interfacing as underlining, fuse it to  shell proir to sewing. Seam allowances are optional.

I used cotton flannel, which will not only add support to my shell fabric, but also make the coat warmer.

1. Your pattern pieces should already be interfaced. I did a quick tutorial on this in the previous post.

2. Cut underlining pieces in the same size as pattern pieces. You don't have to underline pieces which are already interfaced. In any case, don't underline collars, lapels, pocket flaps, cuffs, etc.; those areas are usually interfaced.

3. Place the wrong side of underlining to the wrong side of shell fabric and pin it in the middle, parallel to the grain of the fabric.

4. Now it is time to adjust underlining for turn of cloth. That is the amount of space taken up by fabric's thickness when folded. This has to be done, if you want to avoid bulking of the underlining when you sew the pieces together and press the seam allowances apart. So, place your hand over pins, fold fabric over hand (underlining's overlap shows amount of adjustment needed for turn of cloth), then pin fabric and underlining near adjusted edges. Average turn of cloth will be 0.3 to 0.6 cm (1/8 to 1/4 inches) or more, if your fabric is thicker.

5. Trim underlining to the edge of shell fabric. Pin the other sides to shell as well.

6. Stitch underlining to shell fabric 1.3 cm (1/2 in.) wide with a basting stitch.

7. Optional: to prevent bulk in seams, trim underlining to the stitched line.

8. For extra support: draw lines 2 to 3 cm (3/4 to 1 1/8 in.) apart parallel to the grain of the fabric and hand baste underlining to shell fabric along the lines with stitches 2.5 to 3.5 cm (1 to 1 1/2 in.) long.

9. Trace over pattern's marks for pleats, buttonholes, darts, etc., and sew underlined pieces into a garment.


  1. This is a really great tutorial! I am going to be doing some underlining and you really made this so easy to understand. Thanks!
    xx Easy Outfits, by Pip

  2. This comment has been removed by the author.

    1. Thanks for the information and examples. While watching a class the "experts" stated to cut the underlining as one fabric and then sew it to the fashion fabric as one. I've learned a little about turn of cloth while tailoring but wasn't sure if it applied to underlining. Thanks for the fantasic information.