When working with a delicate fabric that needs to be narrow hemmed, it is often easier and produces a better result to just hand stitch a fine rolled hem rather than trying to use the sewing machine.
I had the good fortune to take a class from Cindy Foose several years ago. Cindy is an amazing sewing teacher and if you ever have the chance to take a class with her, rush to do so! She taught us this wonderful little hand stitch that she called the Toymaker Stitch. I used the stitch when I needed to shorten and then hem my daughter's prom dress. Her dress was pleated silk with a fishtail hem. I needed to shorten it by 6 inches and then hem it without distorting the pleats. This stitch came to the rescue! The wonderful thing about the Toymaker stitch is that unlike an heirloom roll and whip, the Toymaker stitch works on any type of fabric, including difficult to manage polyester. It also works on curves (including fishtail hems)! At the bottom of this post is a video tutorial so you can the magic of this stitch, but the steps are also written out.
1. Use a Sharps or Milliner Needle
To begin, use a number 10 or 11 sharps needle and thread to match the weight of the material being hemmed- a thin and light thread for thin and light material, a heavier thread for heavier fabrics. You can also use a milliner's needle. For this tutorial, I am using all purpose thread in a contrasting color so you can see what I am doing. The thread does show on the right side of the fabric and gives a handpicked look, so to make it as invisible as possible, use matching and lightweight thread.
2. Prepare the Thread & Fabric.
Begin by knotting the thread. Fold the edge to be hemmed by 1/8" to the wrong side, finger pressing it as you go along, and bring the needle up through the fold, burying the knot in the fold.
3. Stitch up and Down pulling the thread to just lie flat on the fabric.
Take the needle directly back down beneath the fold and pick up 1 or 2 threads of material.
Insert the needle into the fold right where it originally came out and travel 1/8" in the fold to the next position.
Keep moving along this way - take a few threads beneath the fold, move up to the fold, inserting the needle where it came out and then traveling 1/8" inside the fold. Do not pull the thread tight as you do this.
4. Slowly pull the thread tight to roll the hem.
After completing about 2 inches, slowly pull on the thread and watch the magic happen! The fabric will roll over on itself creating a perfect tiny hem!
From the right side, tiny prick stitches show.
Here you can see a section of hem that is completed and a section where I am continuing the stitch before pulling on the thread.
Here is another look at the finished right side of the fabric with the tiny prick stitches.
The toymaker stitch isn't one that I use often, but when there is a delicate fabric to hem and a narrow hem is needed, it is the stitch for the job! Here is the video if you would like to watch.