Can someone look at this and tell me where I went wrong?

First time sewing knit fabric...this is a baby hat.  I wanted it to be nice and snug at the bottom, but when I topstitched it, it got all flared. 

I didn't use a ball point needle - would this really make a difference?  I used a double overlock stitch (on my sewing machine - don't have a serger), ummm....trying to think of any other helpful info...here are links to pics...

http://farm5.static.flickr.com/4018/4272772764_cc4546e479.jpg

http://farm5.static.flickr.com/4012/4272027955_16e52897aa.jpg

anyway, can someone help me? 

Rachel

Okay, I warn you that I might not be of any help and I have only worked with jersey a handful of times, but from my experience... ball point really does matter, that flaring seems to be part of working with jersey, ironing sometimes helps, and lastly maybe cut it at a slant so it goes more in at the bottom... does that make sense? 

Hope that helps.

I haven't had good experiences working with jersey on the regular machine. One thing that does help however is stabilizer. Even if you use tissue paper, the kind to wrap presents with, and then tear it away after you are done stitching.

I think this is exactly why ribbing was created. 
Ribbing has more elastic which can handle the stretch and still keep it's shape.
Also, the needle is important because it help pierce the fabric correctly therefore help with the stretching.

Stabilizer is a good idea.  I often use paper towels (off the roll hanging in the kitchen) and either a roller foot or teflon foot. If you have an even feed attachment (walking foot) the layers won't feed separately and therefore, not spread. 

I use a ballpoint needle when I'm working with knit fabrics, perhaps you could use a small zig zag stitch and don't stretch fabric while stitching hope this helps

I've only sewn a few knit items.  Still a bit scared of them as I've had similar problems topstitching around a neckline.  What has helped me some is reducing the pressure on the machine foot so that it doesn't stretch the fabric while it's feeding through.  And like others I agree a ball-point needle helps.  My machine was missing stitches on a regular needle, but once I changed to the ball-point that problem was fixed.  Good luck!

I just joined and saw your message. If you want stretch in the area where you did your topstitching, you need to avoid stabilizers and also to avoid using too much thread in the area.  As one responder said, a simple narrow zig-zag stitch works well. In addition, GENTLY stretch your fabric as it goes under the presser foot by holding the fabric with ONE HAND IN FRONT of the needle AND ONE HAND IN BACK of the needle. Do NOT pull the fabric through the needle area, you still want to let the feed dogs move it through normally - you are only opening the knitted surface of the fabric, so be sure to apply equal and even pressure before and after the needle....and as others said, do use a ball point needle because it will help eliminate skipped stitches.  If you have done this (slightly stretching the material) you will see that it will be slightly fuller when you are finished the stitching - however, once you wash the fabric, it will return to it's normal shape.  If you have used a stitch that puts too much thread into the fabric, the fabric can never return to it's natural shape because of the "stuffing" of the threads. Does that make sense?

I've had that problem too.
I think everyone has great info and
covered all the mistakes I've made
using knits!

Mine was primarily pulling and stretching
the fabric.
Also I had the pressure on the foot too
great, tension too tight, and wrong size
stitches..!

I was just glad I was repairing something
I didn't have to wear out in public.
The Fashion AND the sewing police would've
been alerted with an APB~!

:)Elaine