One of the benefits of an internship (one of the million benefits, I should say) is learning amazing techniques you may not otherwise stumble upon elsewhere. Today I learned a method of sewing a baby hem (or a narrow rolled hem, used for hemming chiffon and very delicate fabric) from Sam and the Row's amazing tailor, Ivan.
In the past, my baby hems have always been ugly. Frayed ends stick out, the fabric stretches and then curls, and the hem width is horribly uneven. The trick? You need something called ban roll, a starched plain-weave tape. Here is how to use it!
The first step is to prep the ban roll - you will use it to sew the seam, but you will remove it afterwards, so you can use it over and over again (hence buy a large amount, like 5 yards, to cover the maximum amount of hemming you'd ever need for a very full skirt, and you only need to prep once). Start by trimming off one edge, where the threads are woven a little tighter. The beauty of ban roll is that it allows you to sew a baby hem as small as possible. To achieve this, the next step is pulling out around 3 of the lengthwise threads. You will end up with something that looks like a very short comb, as in the right hand picture. Since most baby hems are preferred as small as possible, three threads should be all you need to remove (you can remove more, however).
The next step is done incorrectly in the photos, but I will show them anyway for clarification. Here, you can see that I lined up the ban roll to the edge of the chiffon and pinned (like you would hem tape). However, for a cleaner finish (and no risk of sewing into a frayed edge that will later come undone), you would really want to pin the ban roll about half an inch from the chiffon edge, so the stitches will catch fabric that has not frayed for a more secure hem. In the second picture, you can see how the ban roll lines up with the needle - the next step is to stitch up against the woven part of the roll. You want to make sure your stitching stays within this "comb area", and not into the woven area, because you will be pulling it out later. If you stitch into the woven area, you cannot pull it out!
This is where the magic happens. The next step is to flip the ban roll to the inside, against the wrong side of the fabric, once again just as you would hem tape. The baby hem, therefor, will wrap around the comb part of the ban roll (which is why it is ideal to only remove about 3 threads or so - again, you can do more, as you are in control of where you place your stitch line, but I found it easier to line up my needle with the edge of the woven section so I kept the comb the width of my desired finished hem). Once you have wrapped the fabric over the comb section, stitch right down the middle as in the right hand picture.
Once your stitching is finished, press the hem with the ban roll still intact. Then, carefully pull out the ban roll! If you stitched correctly, you will have only sewn onto the comb section, and not into the woven section - thus holding the roll into the hem just enough to sew, but then once finished it can simply be pulled straight out! In the second photo, you can see just how narrow the finished baby hem is - and how straight! The ban roll is sturdy and does not allow the delicate fabric being hemmed to stretch at all.
I cannot even begin to say how much this technique will impact my sewing skills! The hem before had always been something I'd dreaded - because I was not proficient enough to sew them beautifully, to me they ruined my garments after they looked almost perfect. One of the seamstresses swears by ban roll - and sews every seam with it. Now I can see why.
Hope this makes sense!