The big deal about bias tape is this: Bias tape will go round curves without having to be folded.
Hi there! First, there's a difference between "bias" and "bias tape". Bias tape is fabric strips cut on the bias, which is 45 degrees to the grain of the fabric. The strips are usually folded in and pressed. Bias cut fabric, when it's not cut up into strips, usually has a little stretch to it, and has a little swing to it. You can tell the difference really easily by looking at two A-line skirts, one cut on the bias and one cut straight. Bias tape is used to bind edges or make hems, or can even be used for straps. It comes in single fold and double fold, or you can make your own.
Ribbon is woven as a single strip of fabric on the straight grain, where even commercial bias tape is cut and joined. Ribbon can be used instead of bias tape in some cases, but it's not often recommended.
Hmm, okay. So is ribbon not generally used in sewing then? I was planning on sewing some homemade bias tape onto the hems of a shirt I'm [attempting to] reconstruct.
I just wasn't sure *why* it couldn't be ribbon.. so basically it's just easier right?
For your second question, knits tend to be a little more finicky, and if you don't know how to work with them, you may get frustrated or disappointed. That said, if you research them a little bit, there's no reason NOT to use them! They're great! Some of the first things I made were with knits, because they're pretty forgiving. They're mostly used for clothing and costumes. You don't want to use them for bags or purses. You want to use a ballpoint needle, a zig zag or stretch stitch, and hold the fabric taught, but not stretched all the way out.
I broke apart an old knit sweater to convert into my sewing machine cover, and it seemed to stretch on its own under the needle! You just gave me confidence to keep trying with the knits
Thanks a lot guys, that was a lot of helpful information!