Sew briefs elastics

It can be a little tricky to get waistband elastic for underwear right and looking good, so in this guide I describe the method that I use.
I have used the Damienkallingar pattern in this description.

As material is needed, in addition to the material for the underpants:

• Fabric pen
• Ruler
• Pins

You can click on the images in the description to make them larger.

Start by finishing the underpants so that only the elastic waistband remains.

At the bottom edge of the elastic's wrong side, measure 1 cm from the bottom edge and draw a line along the entire elastic.

Overlap the ends of the elastic and pin them together. I have cut my elastic with a 7 mm seam allowance on each end, so I overlap them by 1.4 cm.

Any method is fine except the bad ones. You can sew the elastic together in the way you prefer. Some people sew a square with a cross inside. For underwear elastic, I prefer to zigzag over both ends.

Make markings on both the elastic and the waistband edge of the underpants: center front, center back, center right side, center left side.

The markings should now have equal distance between each other. For example, if the elastic is 58 cm, you will have 14.5 cm between each mark. If the underpant waist is 62 cm, you will have 15.5 cm between each mark.

Match the marks on the underpants with the marks on the elastic and pin them together so that the fabric is level with the line you drew on the elastic. The right side of the fabric should be against the wrong side of the elastic. (The edge of the underpants should thus be inside the elastic). Stretch the elastic between two pins and attach a few more. Do this all the way around the elastic.

Now you need to sew the elastic in place. I use a zigzag stitch, but you can use any stitch you prefer, as long as it stretches.

Place the sewing project with the elastic facing down towards the machine, so you can see the fabric and the wrong side of the elastic. You will now have the ability to see that the fabric is sitting against your line and lying smoothly against the elastic.

When you sew, you need to stretch the elastic so that the fabric lies flat against it. You should not stretch the fabric. Sew with a 7 mm seam allowance. While you sew, also make sure that the fabric stays edge to edge with your line on the elastic.

If it starts to pull or if the fabric starts to "bubble up" (meaning the fabric is too long so it folds over and creates a pleat), stop sewing, put the needle down, lift the presser foot, adjust the fabric and elastic. Then you can start sewing again.

You have now sewn the elastic in place and hopefully achieved an even and nice-looking seam.