Cordage is just what it sounds like, it’s a long, narrow trim, shaped like a cord. It can be smooth or textured and made from practically any material – from cotton to hemp to leather. As well as a trimming, it can serve a functional use as a drawstring in a garment.
Piping is a cord that has been covered with a strip of bias-cut fabric which is, in turn, sewn or glued shut. When trimming a costume or piece of upholstery, it can be used in a complementary or contrasting color. Piping fabric can also be made from a variety of materials – from cotton and blends to wool and even vinyl. Yup, vinyl piping is a thing, although you’ll mostly see it on furniture.
Piping can be a lot easier to attach to a costume than cordage because piping offers that selvedge edge. You place that inside your seam allowance – I recommend hand-basting it to a single layer of your fabric first, and then pinning the seam together – and then sew it with a zipper foot to ensure you get close enough.
Craftsy tutorial on attaching piping and turning corners.
If you’re applying a lot of narrow cording, consider investing in a cording foot for your sewing machine, because sewing it by hand is a short cut to a nervous breakdown.
Demonstration on how to use a cording foot.
In a moment of madness, you might consider gluing cordage on to your costume. Don’t do it. Just don’t. The glue WILL be visible and it’s very difficult to get enough contact between the cylindrical cord and the surface of your fabric to ensure that it’ll actually stick.
Sometimes, you’ll find a fabric that would be perfect for trimming a costume, but you can’t find piping or cordage to match. Good news! You can make your own piping from a fabric pretty easily, as long as you remember two things.
First, if you’re using a woven fabric for your piping, cut the fabric on the bias. You need the stretch from the bias cut to help your piping navigate curves and corners without wrinkling or splitting.
Secondly, remember to account for the thickness of your cordage AND your covering fabric when creating your trim. I once accidentally created a piping for a Battlestar Galactica uniform that was far too thick for the purpose because I picked a base cord that matched what I wanted for the finished item – I didn’t account for the bulk that was added when I put the fabric over the top of it. Oops!
Sewing piping on to a costume is pretty easy as long as you don’t muddle up which way is “out” when laying it down. I’m forever accidentally putting my piping on the inside of my garment, which is a reason why I avoid making heavily embellished costumes.
The washability of your trim depends on what materials went into making it, so pay attention to the labels when shopping.