Dec 2011 Update: Hem roll? Not anymore! Part 2 ~~~~~
I took pictures this time of a knitted swatch, lace, standard gauge. It doesn’t take but a minute more to knit the beginning edge in this manner, and it’s easier to demonstrate, to measure for gauge later, and to block it so the lace opens up real nice. I figured a picture is worth a thousand words. Mm, somebody else said that once, I think. So here you go. This swatch is right out of the washer and dryer:

Right out of the dryer.
You’re thinking, Hem roll! Right? Yes, but it’s in the waste yarn, so follow me to the second picture, where I am removing the waste yarn:

The "roll" falls away with the waste yarn.
Look how that hem roll disappeared. It’s so much easier to measure for gauge, and when I go to block it, I won’t have to fight hem roll at the same time. This yarn sample is Millor Tepeyac, an acrylic / nylon blend.
Nov. 2011 ~~~~~~
Months ago, I machine knit some sleeves on a sweater from the shoulder down. I made them extra long, as I wasn’t quite sure what length I wanted. My yarn was 75% acrylic, 25% nylon. So I assembled the sweater, washed and dried it, tried it on, and discovered I needed to ravel about an inch. When I did that, the edge roll disappeared with the discarded yarn and did not come back!
Yesterday, my goal was to duplicate this wonderful, flat, no-roll edge. But I wanted it on the bottom of my sweater this time, and I didn’t want to knit it from the top down. Time to experiment, trying the waste yarn trick on the beginning edge. This yarn was 65% acrylic, 35% rayon. Standard gauge machine, lace pattern.
Here is what I did, step by step:
1. CO w/ CO rag.
2. K1R w/ ravel cord.
These first two steps can be skipped if you don’t have a CO rag; I do it to make the job go faster.
3. Ewrap ndls w/ waste yarn and K 15 Rs. This is a case of “more is better.”
4. K1R w/ crochet thread (using it like ravel cord, but this one will be cut before washing, and I didn’t want to cut my ravel cord).
5. Ewrap ndls w/ MY. This is the actual hemline.
6. Begin bottom edge of garment or swatch. I was doing a lace swatch.
7. K number of Rs desired and finish as normal.
8. Remove ravel cord and CO rag.
9. Cut crochet thread so it doesn’t tangle in the washer, but do not remove it or the WY.
10. Wash and dry as desired.
11. At this point, when I removed it from the dryer, the waste yarn rolled, but not all the way up to the beginning of the swatch. I probably could have removed it and had a flat edge right then, but the swatch was so wrinkled anyway, that I’d want to steam the final garment, so I pinned it to a board, steamed it, then let it dry.
12. As usual, steaming did not completely flatten the bind off edge; it left a hint of a roll. But when I removed the crochet thread and WY, the cast on edge was wonderfully, beautifully flat. No roll. Not even a hint of a rolled edge.
Success!
I won’t always use this edge, but for my next lace sweater, I didn’t want ribbing or a folded hem. This is the answer. I thought I’d share it here in case anyone else wants to try it on his or her next gauge swatch–I mean, what a perfect time to try it, right? Just a few extra waste yarn rows BEFORE your first CC row, so you don’t have to do a separate swatch to test it.