I've been given some pa speakers and I would like to make slip covers for them from some old curtains. I was thinking of just making a tube that slides over the speakers but if the cover is too flexible it won't start to slide easily. I don't want to go with a full structured, panelled cover partly because that sounds like lots of work but mostly because I want the covers to pack down small when they're not in use. So I was thinking of making the tube and then adding piping to the corners.
Yes, you most certainly can! Either rigid pipe like Sebastian said, or fabric piping.
Pro tip: Put your piping in before you sew the final shape, it's much easier if you aren't trying to work with adding to a shaped form. If you are using rigid, make the channels, if you are sewing in fabric piping, stitch it in. Also keeps you from ending up with it too small because the channels took it in a bit more than expected.
Personally, I'd use fabric piping, it's easier, or, me being me, I'm a dumpster diver type, I'd use plastic strap, it's all over in trash. You also might look at the fabric you are using, see if you can just fold a few layers and stitch them down and add body that way. Look at this thread1890s Pretty Housemaid Corded Corset - historybounding for modern farmlife for seeing how they add a lot of body, you don't need anywhere near that much, but it's a good example.
All you are trying to do is add a bit of body, and it won't take much to do that.
Pearl, that video looks insane! I'm not up to shaping shorts and trousers so a corset is definitely out but the cording process looks simple enough. Normally I would roll the seam but with the piping/cording I'm thinking a tape (binding?) would work better.
I'd be looking at fabric piping just to keep it flexible when stuffed out of the way.
I'm much more comfortable with metal or wood, it stays where I put it and doesn't strecth in weird ways.
Yeah, that IS an amazing process. But what I wanted you to see was how sturdy they were getting things and how tight it was stitched down.
If I were making your cover, where I wanted a corner, I'd fold it, stick a piece of piping in it, sew it tight against it, unfold it, there's your corner, go on the next one. Cut your fabric either bigger, or after you sew in the corners. I'd sew a corner, measure to my next, sew it in, measure to the next, keeps you from ending up short of cloth, then put a back seam that isn't involved with the piping for my final.
Sewing piping takes some skills if you are a beginner, also I found . cotton cords absurdly expensive in fabric store.
I sew lots of pet beds for donation but don't want to spend extra for pipings. The way i do it is just sew fabrics layers wrong sides together, turn over and sew a second time right side together. Not as pretty but that''s enough to give the edge some structure.
Any foot that has a narrow edge. You want to sew as- close to the stuff as you can get. I'd use a zipper foot, just because I have one sitting out right now, easy to grab.
And I'd probably use cheap cotton clothesline, cheaper than tent line, if we are thinking the same stuff. And I have some actually on the floor right by my desk (the cleaning elves around here REALLY need to do their job better! This whole area is a mess!)