Serger Rolled Hem

A serger rolled hem can be done with 2 or 3 threads, depending on the capabilities of your machine. The 3-thread is generally easier to control. The 2 thread gives a more delicate finish sometimes nicer for fine sheer fabrics.

Follow the manual to set up your serger for rolled hemming. On newer machines it often just involves sliding a lever. On others it might require changing the needle plate. Additionally, if you intend to use only 2 threads, there must be a mechanism by which the upper looper is bypassed. (On my previous serger there was a small metal piece that fit into the upper looper allowing the lower looper thread to ignore it.)

Always experiment on scraps before starting on your actual piece.

Many people want to keep a record of exactly what settings work for a particular stitch. It's common for people to keep a sort of serging journal - when they find a stitch they like, they staple a piece of the serged fabric to a paper on which they've recorded all the tension, stitch length, differential feed, and cutting width settings. That's fine and actually a good idea in the beginning.

However, chances are that next time you go to make the same stitch, the settings will be a little different. So it's important to realize that when you pull out your stitch reference your settings will be relatively similar, not identical.

For example, for a 3-thread rolled hem, the lower looper tension will be higher than the needle or upper looper tension, and the stitch length will be somewhat lower than usual. The lower looper tension will not always be, say, 7. There are just too many variables to anticipate - fabric content and weave (i.e., georgette or chiffon?), cut of the fabric (true bias, partial bias, cross-grain, lengthwise?), thread content, type, and tension on the spool, needle type and size, even weather. (Yup, I truly believe the weather matters!)

Variables

Use your scraps to fine tune the settings:

• Sometimes you might want more thread coverage for a prominent roll, other times you might want the stitches to be very open and inconspicuous.
  
• You may want the smallest roll possible, in which case you can try tightening both looper tensions even further, decreasing cutting width, and/or changing thread types (mono-filament nylon, for example, is quite elastic and might squeeze the roll tighter.) A 2-thread hem will also be more delicate than a 3-thread. ~
  

• You may want an obvious, prominent roll, as for table linens or accessories. Try increasing cutting width, using a smaller stitch length, and perhaps a fatter thread, perhaps a beefy decorative thread such as perle cotton or ribbon. (More on serging with specialty threads in a future post.) You might even run some cording into the roll to give it some heft and stiffness. Remember, you're the boss. This rolled hem was done with a thick gold metallic decorative thread ~

• You can run wire through the roll (very carefully so it doesn't hit the knives) and make your own wired ribbon.
  
• You can run fishing line through the roll for a graceful, scalloped edge. (more in a future post.) ~

• You can attach lace or other trim with a rolled hem. This is an especially elegant application ~

• Run over a fold without cutting, the rolled hem makes nice pin tucking.
• Note: You can use rolled hem settings without actually rolling the fabric. The idea here is to increase lower looper tension relative to upper looper tension. The upper looper thread will then wrap completely around to the back of the fabric, giving the nice coverage of a rolled hem without the rolling. Especially useful for finishing the edges of thick decorator fabrics. You can do this over the regular stitch finger while cutting for an even edge.
  

Problem Solving

Whiskers - This is how I describe when fabric thread ends stick out from the rolled hem like, well, whiskers. It can be especially problematic on bias cuts. There are several ways to deal with whiskers (besides bleach or wax.)

• Try increasing cutting width. Having more fabric in the roll helps those fiber ends become secured inside the roll.
• Try decreasing stitch length. More thread coverage may secure the whiskers.
• Woolly nylon thread spreads over the surface of the roll providing coverage than regular thread.
• Press a fold into the edge of the fabric, then do the serged hem over the folded edge, without cutting.
  
• Run a length of straight grain fabric along the hem as you serge. Understand that this will make the roll beefier and eliminate any stretch.
  

Waving - This is when the hem edge stretches as you serge, forming waves or undulations. Sometimes you want that waviness as it's quite feminine and lacy looking. But if you want a straight edge here's what to do:

• If possible do all hemming on straight or cross grain. (i.e. for napkins or scarves.) Note: cross grain will sometimes wave when straight doesn't. Remember, cross grain is stretchier than lengthwise. If that happens, you may have to turn up differential feed on the cross grain edges only.
• Turn up the differential feed slightly. Anytime you have trouble with a fabric stretching under the serger foot, this is the thing to do.
• Use your fingers to push fabric towards the presser foot as it feeds. Just as you would on a conventional SM if you were stay-stitching.
• Try starching the edges first.

Roll comes off edge of fabric - Don't you hate when rolls get away from you??? Seriously, this is when the rolled hem just detaches from the body of the fabric. It's quite disturbing when it happens. But you can fix it:

• Increase cutting width. This in effect places the stitches further into the body of the fabric, giving them more "grip."
• Decrease stitch length. The denser the stitches, the more perforated the fabric is and the more likely it is to come apart.
• Use a smaller needle for smaller holes.
• In extreme cases, you may have to pre-fold the fabric edge and serge over the fold, as above.

A serger is worth having just for the rolled hemming. It's fast and fun and gives a very professional finish.