If you haven't already,
I suggest reading Ashiya and Naajidah's piece "where have all the cover ups gone?" For a good summary of why you should own and wear one. For the TL;DR crowd: a cover up is your combination backstage curtain and apron. It keeps your costume safer from kitchen (read backstage ^_~) spills and splashes and preserves the magic and awe of your vestments for the moment you take the stage. If you've already performed and are in the audience after, it helps you blend a bit and avoid stealing the spotlight from the next performers.
In this article, we'll look at what makes a good cover up, and your options for getting your hands on one.
There are different schools of thought on using a veil as a cover up, and they seem to fall along the fusion/orientale divide. In vintage American dance, the dancer would enter wrapped in her veil, and use it for the second song. For this reason, the veil is considered part of costume. You want to keep it a surprise and keep it clean. ATS/ITS doesn't usually use a veil in their performances, so it is acceptable as a cover up in those circumstances. Outside of fusion, at performances or events where you have a formal stage with an actual backstage and you won't be moving through the audience without putting on your civilian cloths, a robe over your costume will keep you warm and keep makeup off your expensive, hard to clean costume. On the same lines, a folkloric dress made for performance is not a cover up. This disqualifies things like Khalijy thobes.
A cover up should be almost as long as your skirt and have long sleeves.
Bracelet length is the shortest I would go for the sleeves. For the hem, long enough to cover your costume without creating a tripping hazard. If you're thinking "but my skirt pools on the floor, that's not possible to have a cover up that long" then you need to find someone to hem your costume, because that's asking for trouble and distracting to a lot of audiences.
You want the cover up to open all the way down the front for ease getting on stage. You might find yourself hurrying to the stage, or needing to step out of the audience and suddenly be in costume, depending on the venue, and you don't want to be fighting your cover up over your head, potentially messing up your hair and makeup on the way. It should close all the way, not letting any of your costume show in the middle, and not counting on you to hold it shut.
I love this blue and white cover up, but never wear it. It's not big enough to go over a full skirt or embellished bra and has to be wiggled into from over the head. >
Velcro might seem like a good idea, it's fast and easy, but you run the risk of it getting stuck on your costume. Zipper fronts that separate on the bottom, like on a hoodie, can work but you need a zipper that's long enough and have to be careful not to catch your costume when zipping it on. Ties are ok but I find them problematic if you need to get out of the robe in a hurry and they can tangle, and I don't even want to think of untying one with finger cymbals on! My cover up uses snaps and I'm happy with it.
You might opt for a double breasted design, especially if you enjoy full chiffon skirts, it helps keep you stay covered as you walk and your skirt swishes around. You want the cover up to be full enough to go over your whole costume without squishing it and creating creases, but not so voluminous that it is hard to move around in or creates a hazard of its own.
Consider the neckline as well. Your cover up should fully hide your bra and at least some of your cleavage and/or necklace. Remember, the goal is to not draw attention from the other performers. More than that, you don't want to spill something down your front and into your costume.
On the topic of not drawing attention, there are many beautiful colors, and it's certainly normal to pick something light or even bright. You won't be called out for this, but if you're going to be backstage in a theatrical setting then I recommend black. It helps you hide, as Ranya says: there's a reason stage hands wear it. That being said, if you're primarily performing at outdoor festivals, then lighter colors can help you stay cool in the sun, and probably help you blend into the crowd better, too.
Lastly, pick something that is machine washable. Costumes need enough maintenance, don't add to your workload. Also, Pick something breathable. You'll be hot when you get off stage and won't want to wrap yourself up in velvet while you're dripping sweat.
Sara L Shrapnell includes sewing instructions for this blue and white design in her book "Becoming a Bellydancer". > Leyla Mary of Serena Studios wears pink cover up that zips down the front, covers the full length of her costume, and her sleeves are just wide enough to hide the arm accessories of her outfit without getting in her way if she needs to reach for something. > Elsa's gold cover up is easy on and off, and simple to sew
There are 3 options for getting a cover up: buy one, buy another garment and modify it, or make one from scratch Many costume retailers sell caftans and cover ups. They are usually very expensive and, while pretty, I don't usually find them worth the price. For less than most of those options, try to find a hook up who will bring back abayas from the Middle East. If you go this route, be sure to avoid anything that has religious imagery or statement pieces.
This was my first cover up. A bathing suit cover-up/maxi-dress from j.c. penny. I cut it open down the front and added some pleated quilter's cotton to fill the middle and keep my skirts covered. I made a new one because it didn't cover the top front well enough, without a scarf (veil) worn down the middle. I keep it to lend to students. Wrap dresses and robes of any sort can also work, provided you don't look like you're walking around the restaurant in a bathrobe.
This is my current cover up. I need to do something to raise the neckline, and if I were going to do it again I would pick a fabric that doesn't wrinkle after being balled up in my gig bag. It makes me look like a federal judge, but I like it. I made it by modifying a pattern for a renaissance fair bodice that I had lying around. You can find patterns already intended to be some sort of robe at craft stores, in the costume section of the books or through bellydance pattern companies.