These needles, called Tambour needles, are used in Haute Couture and it makes it easier for the craftsmen embroidering large amount of fabric. I first encountered this item from Sofia Salazar's (@__hiedra__) posts on instagram. I have been lurking in the embroidery community of instagram and noticed a few other people using this needle as well and wanted to give it a try. Theres only one shop in Tokyo that handles tambour needles so I had some struggle, but I was able to get them in the end. You should be able to find a lot of information in tambour stitching on the internet especially in English (or French which is where it's from!).
You need a few practice to get used to it, but once you do get the hang of it, it's so much easier to stitch this way.
And this is the finished piece! It's from this sketch I did of my boyfriend. I love it because it's done in one stroke. Also the simplicity of the stitch really works with the visuals.
I would say you can't use this needle in any kind of situation because this needle generally lets you produce chain stitches. I think the chain stitch has a distinct feel to it, mainly in good ways. The minimal look it gives off is very distinct from satin stitch (is this the correct term? I usually prefer to use this stitching method). Because of its feel, it might not stick with some works I want to create for this project. But it's definitely a fast way to get your design on a piece of cloth and it works for mass production by hand.
Maria
Side Story:
Below is a photo of an embroidery piece I left behind because I got so tired of it. I'm keen to go back to it now though!