Some of you may be thinking—what IS a serger anyway? If you take a look inside your "off the rack" clothing, you'll notice all the seams are trimmed down to about 1/4 to 3/8" and finished off with a bound edge of thread. A serger is a way to stitch seams that are self-binding—the excess seam allowance is cut away as it stitches. Makes for tidy and strong seams. It means that for hemming raw edges, you can simply serge the raw edge and turn up your fabric one time instead of pressing twice as in normal hemming.
I teach students to sew clothes and lots of other things without a serger all the time, so you really don't have to have one to enjoy sewing. However, once you get past the trickier threading and tension settings, the serger is a huge time saver and makes for a very clean, durable finish on clothing, window treatments, etc. It also makes knit seams strong and flexible. You'll always use your regular sewing machine in addition to your serger. The further along you get in your sewing, the more you will recognize the benefits of sewing with a serger.
Home sergers have come a long way since I first used one around 16 years ago. I have worked with many sergers from the most scary industrial early model klunkers to ones i was sure could fly me to the moon, do my taxes and make a fabulous evening gown with the simple press of a button. Truth is, I use a simple Kenmore 4-thread serger which is not computerized and I like it that way. The computerized machines are nice because they are pre-set to switch tensions and other settings depending on what stitch you want to do. I have just found that the computerized models are more machine than I need and I simply haven't justified the extra cost.
I honestly don't have any particular brand favorite, but I would never buy a serger from any chain fabric store or Wal-Mart or Target. I do have a list of several things you really want to look for in any new or used serger. If you are looking at a specific brand and want my take on it, I'm happy to give you my 2¢.
Each company comes out with new serger models all of the time, so it's difficult to suggest any particular model or brand. So, we just recommended you look for a serger that has all of the features that we've outlined below, and is within your budget. Also, you can google any model that you're interested in to get consumer reviews. Just be sure to throw out the best and worst reviews, and know that it's somewhere in the middle. Never purchase a serger without some sort of return policy, just in case!
Differential Feed Contol
Color Coded Threading with "easy Lower Looper threading mechanism"
4-Thread and 3-Thread Serging
Easy Rolled Hemming Conversion
Nice to haves:
Cutting Width Adjustment Knob
Presser foot pressure control knob
5-thread and/or Cover Stitch feature
Differential Feed Control
This is absolutely essential in my view. Most sergers come with this feature, but some do not. Differential feed is a special set of feed dogs that can be adjusted to correct knits or bias fabrics from stretching out or puckering in. Not having it will limit your ability to serge a wide range of fabrics to your satisfaction.
Ease of threading
This is kind of an evil thing to even say because sergers by nature are just kinda complicated to thread until you get used to them. The lower looper is notoriously tricky to get to without tweezers, but many models have come up with good design solutions to make this easier. Obvious bright color coding for each of the thread paths and a set of good illustrations on the inside of the serger front as a cheat sheet are extremely helpful. Once your serger is threaded and you want to change colors you will be able to tie on the new threads and simply pull them through instead of re-threading all over again through all the parts. There are seriously "self-threading" sergers I've played with that use a jet puff of air to push the threads through. There's a learning curve on that and you'll pay big for this convenience.
Ease of switching from Standard to Rolled Hem
A rolled hem is a special narrow, tubular edge used in finishing raw edges of lightweight fabrics. Some machines make it easy to convert from standard serging to rolled hemming with the flick of one or two simple levers or knobs. Others require complete change-out of the throat plate which is more time consuming and cumbersome. I make simple bias cut flowy chiffon, georgette or charmeuse skirts by first serging my side seams and then finishing the hem edge off with a rolled hem. Being able to covert easily (not having to change the whole throat plate) is a time saver for sure.
Cutting Width Adjustment Knob
This knob simply moves the cutting blades out or in to let the stitches lay right on the edge of the fabric you are serging. Different densities, thicknesses and number of layers require different settings.
Presser Foot Pressure Adjustment Knob
If you're going to do thick layers like heavy lofty baby cloth diapers or polar fleece you're going to want to be able to adjust the presser foot pressure to ease up so it doesn't grind into the fabric which causes stitches to bunch up and fabric to stretch out.
Cover Stitch and 5-thread serging
Cover stitch is the hem you see on all t-shirts. It looks like two rows of stitching on the right side of the fabric and the raw edge is covered flat on the wrong side by serging. Many new higher end sergers (read: 'spensive) have this feature and it's totally worth it if you're into making lots of knit garments--sportswear, swimwear, lingerie, etc.
5-thread serging tosses in a third looper into the equation and is a true "safety lock" stitch. Look at the inside of your blue jeans and you'll see this stitch. It is super firm, super secure for those kinds of heavy duty seams that get a lot of wear.
Both cover stitch and 5-thread are cool features to have but not worth the extra dough and hassle if you're not interested in the above garments.