Seam Finishing Techniques

When I made my first few outfits, something that I didn't know about (but really wish I did) was seam finishing. I was never really "formally trained" at sewing, so nobody had ever explained to me that if you didn't finish the seams of your garments that they would fall apart the first time you put them through the wash. If you've ever had this happen to you, then you'll know that this is indeed a very sad thing.

Now, there are plenty of ways to finish your seams, and I can't cover them all, but I will talk about a few common ways to do it. Some of these require extra equipment, while others work best when hand-stitching.

Serger:

Probably the easiest and most-straightforward method of finishing your seams is by using a serger. Now, you're probably thinking, "What's a serger?" Simply put, it's a special kind of sewing machine that finishes edges and they look like this:

Finishing seams with a serger basically involves running the machine around the edge of each piece of fabric before you sew them together. It really couldn't be any simpler (unless you could figure out a way to never need to thread one). Sergers also typically trim the fabric edge so you get a nice clean finish. For an example of a serger-finished edge, grab the nearest t-shirt, turn it inside out, and take a look at the seams. You'll see that they are essentially wrapped in thread. That is what a serger does. The major drawback of a serger (aside from the difficulty in threading one) is that it requires an extra piece of equipment, and they aren't exactly cheap. It is worth checking with sewers in your local group to see if one of them has a serger that they'd be willing to let you use for your project (I don't own one, but borrow my roommates when I need to use one). If you can't find a serger, you can approximate the effect by using the zig-zag stitch on a regular sewing machine. It won't be quite as strong or as neat, but you can get pretty close with careful stitching and trimming (Of course this requires you to have a sewing machine as well). 

Felling:

If you find that you lack the fancy machines necessary to serge/zig-zag stitch the edges of your garment or if you want a more medieval look, felling your edges might be for you. Felled seams often appear in canvas tents and sometimes jeans are constructed using them. Felled seams are a historical method of assembling garments and are quite strong (which is why they're used in tents). If you are sewing by hand, this is probably your best bet for most seams. Essentially they are done by having the two pieces of fabric (blue and green lines) wrap around each other as shown in the image on the right. They can be done by hand or using a sewing machine. The orange lines show roughly where the seams go when hand sewing. I like to do these by overstitching. This is shown in the image below:

For machine sewing, you can get a special presser foot to help you make them, but this is unnecessary. Unfortunately you'll find that there really isn't a way to do this without creating a visible machine stitch, which is something I like to avoid when sewing medieval clothing. However, you might find this to be acceptable, particularly for undergarments (shirts, braies, etc). Furthermore, you can create a hybrid where you do the first seam stitch with a machine, roll the felled seam over, and finish with a hand stitch (hem, overstitch, etc). 

This is another good explanation of how a felled seam works: http://www.backpacking.net/makegear/tarptent3/flatfelled.html

This is a reasonable tutorial for how to make them using a sewing machine: http://www.coletterie.com/tutorials-tips-tricks/standard-flat-felled-seam

Rolled:

Another way of finishing edges is to roll them over. This tucks the raw edge inside the roll so that it can't unravel. Rolled seam edges are shown above, and they can be carried out in a couple ways. The neatest way is to put a narrow hand-rolled hem around each piece and then sew the pieces together, but a quicker way to do it is to simply stitch your fabric pieces together, leaving a wide seam allowance (3/4" - 1.5" depending on how much fabric you need to leave yourself). Then, simply fold this seam allowance over twice, tucking the raw edge inside, press with an iron, and stitch the edge down (by overstitching, hem stitch, etc). You can also do this with a sewing machine, but like before, you'll have a visible machine stitch (unless your machine can do a blind hem stitch, but most can't). 

This is a good tutorial on doing a hand-rolled hem: http://hubpages.com/hub/How-to-sew-a-rolled-hem

For a quick reference sheet to some basic sewing stitches, look here: http://www.ia470.com/wardrobe/stitches.html

Note: What I have called overstitching during most of this tutorial is referred to as a "whip stitch" by this stitching guide. For rolling over and finishing hems, there are several stitches presented in this guide that will work just fine including the whip stitch, vertical hem stitch, cross stitch, and even slip stitch. However, you will probably find that the simpler, spiral ones are a bit faster.