proudblond , 5 hours ago

I feel like most of the people answering you are not actually sewists.

The person mentioning the serger/overlocker machine is correct regarding stretchy material. You can do it on a sewing machine but it won’t look nice. On a regular sewing machine, a straight stitch will give you a non-stretchy seam. A zigzag stitch will be stretchy but most often people aren’t pleased with the look of it. If you look at the inside of a t-shirt, the side seams are generally done with a serger. (A coverstitch machine is usually what is used for a hem. It makes a row of two lines on the front. It only does that.) The reason a serger works better for knit fabric is because of the differential feed, meaning it can better handle sewing two stretchy fabrics together such as in a seam. A sewing machine only feeds by catching the bottom fabric and scooting it forward, and that can cause issues if the fabric is stretchy.

You also need appropriate needles, especially for something like spandex. I haven’t worked with it at all so I’m not sure 100% what to recommend, but possibly a ball point or microtex needle.

Meanwhile, for upholstery, all you need (I think) is a straight stitch. Technically you could even try to do it by hand, but depending on the material, it could be really difficult. You’d definitely need a heavy duty needle, and possibly pliers to pull the needle through thick fabric. If you went for a machine, you’d want something robust. I’m actually about to try an upholstery project using my mid-range Bernina; it has successfully sewn several bags so I think it can handle it. But Bernina is not a mid-level brand, and I spent good money on that machine. Certainly, like in most things, you get what you pay for.