This is yet another one of those posts that doesn’t really have a distinct answer. Costuming for puppeteers can be extremely varied, dependent entirely on the director’s vision, the blocking (theatrical term for "movement"), the content of the show, and whether or not the puppeteers are seen on stage. However, there are some general concepts which are good to keep in mind.

1. The puppeteer, no matter whether they are visible or not, should be comfortable at all times. Much like in dance or circus, puppeteers must have the flexibility to move freely in their clothing, without fear of tearing, tripping, general restriction in movement, or having parts of their costume interfere (or get caught) with their puppet.
2. The clothing should therefore also be light in weight; thin materials are better, as they allow the puppeteer to remain cool underneath hot lights and whilst exerting themselves onstage. (Puppetry is also, just like dance, very tiring and … yes, sweaty!)
3. Shoes, gloves, hoods and other items also merit discussion, and I will do so in more detail below. Although as a general rule of thumb in theatre, it’s best to leave your jewellery at home; unless it’s part of the costume you have been directed to wear.
4. If the puppeteer also acts as a character separate to their puppet’s character, the costume may be distinctly in contrast with the puppet itself. However, as a general rule of thumb, the puppeteer’s costume if visible, should not distract from the actions or character of the
   puppet. (In this context, it’s easy to explain why many visible puppeteers, such as those in Avenue Q, wear light grey, dark grey, or black. These colours are neutral, and easy to blend in with the sets/props/puppets, no matter what the setting is)
5. If the puppeteer is to be ‘invisible’ using light curtain or blacklight, then the person should be covered head to toe in black. A much more detailed explanation has already been written here.
6. Costuming can often be more than clothing; see costume puppets for more info.

Even with having puppeteers visible on stage, there are a variety of ways to do it. Puppeteers can dress a la bunraku, with black costumes, hoods and gloves; some leave the face visible (that is, no hood) but remain wearing gloves and black costumes. Others prefer no gloves at all (it can hinder the dexterity of the puppeteer, as well as make it harder to sense nuanced actions through the puppet); even in wearing black, variety can arise, through male/female differences in wearing pants versus skirts respectively. Not to mention the fact that costumes can be of the non-black, non-neutral variety (see below).

‘Invisible’ can mean many things as well, since puppeteers can be visible to the audience, but not lit, so they remain a shadowy figure upstage. In my first self-produced show, we had gone with the use of a light curtain, but on arrival discovered the lights were silver-painted. In order for light curtain to work, the whole room must be in black, even the paint job of the lights directly above us (this was a non-theatrical room done up for the event with platform, black curtain and temporary lighting rig). But amazingly, even the reflection of these silver lights were not enough to counteract the light curtain effect, and the audience was so busy watching the puppetry, they did not notice the slight appearance of us puppeteers working below the silvery lights.

Another factor is whether or not you have something to hide behind. In many Asian forms of puppetry or when working on film or TV, there is a ‘hide’; a false wall which you can stand/kneel behind. In this situation, puppeteers raise their arms above their heads in order to present the puppets to the audience, and are not seen at all. And when working behind a shadow puppet screen, you are likewise not visible at any point. In these situations, puppeteers may wear whatever is comfortable to them, with no concern about aesthetics.

Should the puppeteer be visible?

This is probably a longer discussion than necessary here, but suffice to say that it’s entirely up to you. Some people think seeing the puppeteer (or the puppeteer’s skin - hence the gloves and hoods) is distracting to the audience. The truth of the matter is that if it’s good manipulation, an interesting and engaging story, and genuinely believable acting, then the audience won’t even see the puppeteers. Indeed a lot of audience members will remark after performances how much they forgot about the puppeteers altogether. Gloves and hoods and all that jazz is entirely subjectivel unless working in blacklight, green screen or light curtain. From a personal point of view, I prefer the ungloved look, I enjoy watching the intricacies of the dexterous hand movements, and I like being able to see the engagement on the face of the puppeteer. In actual fact, in certain contexts (such as using rods that are not black), the contrast between gloves and the puppet can also be just as distracting as seeing skin.

… We’ve discussed briefly comfort and visibilty, but the context of the play and the director’s vision also comes into it. Puppeteers do often interact with their puppets - especially in ventriloquism - so having an appropriate costume to go with the performance is a good idea. Aussie puppeteer Murray Raine performs cabaret acts, and as you can see by his costume, it is in keeping with the glitz and glamour of cabaret. Blackhole Theatre’s Coop, which is set in a chicken coop, has their puppeteers dress in a slobbish, outback manner. Asyphyxia’s The Grimstones is a gothic marionette performance, and the performers wear appropriately dark outfits. Just from these three examples alone, you can immediately see that puppeteers do not have a ‘traditional‘ costume, but rather a wide variety of options depending on the style and content of the play. I can imagine it would be a wonderfully simple idea to combine recycled costumes with puppets made out of recycled materials. Indeed, at one university show I did, we had a costume (a dress for a homeless woman) made entirely out of coloured plastic bags woven together.

…But now let’s turn our attention to some of the details of common costuming for puppeteers.

What kind of gloves should you use?

This one again is more about comfort than aesthetics. Some puppeteers find that wearing gloves with fingers are too difficult (for reasons mentioned above), and indeed with thicker gloves, it is not that great for dexterity. So some puppeteers - especially those working with muppet-type puppets - prefer fingerless gloves. Choice of material is important too: for example ladies’ evening gloves are shiny and slippery, not great for creating good grip with your puppets or for hiding in blacklight. In fact, I have a pair of homemade gloves using a soft, light, almost-fleece material. They are actually long enough to go just over my elbows, and have elastic at the opening. If you’re working in light curtain, blacklight, green screen, or in any situation where you want to avoid seeing skin, then long gloves are a good idea. The length ensures your arm will never been seen, even when wearing long-sleeved tops, and the elastic ensures that no matter how much you exert yourself onstage, the gloves will never sag or fall down - both something easily seen by audiences, and frustrating when trying to manipulate puppets and hold your clothing up. 

What kind of shoes should you wear?

I’ve often heard puppeteers stating that they prefer to wear socks on stage; even soft-soled shoes like dancers wear. However, as a stage manager and someone trained in theatrical OH&S, I can tell you that’s a really stupid idea. In fact, I have a better reason for saying that. When I was 10, I dropped a nine-pound bowling ball on my left foot (don’t ask why, and yes, it hurt). I’ve seen stilt walkers fall (and been trained to do it safely myself), techies get hit on the head with spanners from people working above, I’ve personally seen a circus performer accidentally kick a ring as he was diving through it and get hit in the head and immediately rushed to hospital when he - and it - landed. I’ve worked ten metres above the stage on a see-through metal platform and watch a rigger (luckily harnessed) fall from it. I’ve seen a friend and colleague fall right through a block of steps as soon as he stood on it, in the middle of a performance. This is just a very small sample of the dangerous things I’ve seen or done in a theatre, and I’m very safety-conscious. Wearing shoes is a small price to pay to ensure you don’t stand on broken glass (says the puppeteer who dropped a glass bowl prop onstage whilst packing up one night), don’t stand on any nails lying about from building things, don’t get hurt in the dark with a puppet’s rod or puppeteer’s elbow, and don’t have heavy theatrical lights landing on unprotected feet. So really, my advice is: wear shoes. Any kind of shoes that are comfortable, won’t hurt you (ie. blisters, falling apart, etc.) and will protect your toesies. Take it from me, it may not stop you from getting hurt, but it will make it less likely and much safer all around.

What kind of hood should I wear?

If we’re talking light curtain or blacklight, then a very simply hood can be made. From memory, my friend Jeany made us some to wear for our show, and it comprised of a series of straight panels for around the face, joined into a tube, and then a circular piece added to the top (imagine a tin can sort of shape, with the lid removed, almost Ned Kelly style). To allow the puppeteers to see, a rectangular area is cut out of the hood at the eyeline, and replaced with a piece of black mesh. The mesh is see through (because of the small holes in the fabric), but not so see-through that the audience can make out facial features. This mesh is also used in costume puppets, where the puppeteer’s eyes are not in the same place as the costume’s. Hoods can be found at any number of blacklight puppet sellers online, but they are very easy to make and someone with basic sewing skills would have no trouble making it. Whatever you do, make sure the hood is light and breathable. Attaching the hood to the neck of a costume is a pretty bad idea, since it makes removal difficult (especially in an emergency) and breathing harder. It gets very hot inside the hood. Instead, ensure it is long enough to cover the neck, and let it hang free over the head and down to shoulder level. In addition, a plastic band or circular brim inserted into the top of the hood will aid in making sure the fabric doesn’t constantly rub the face or make breathing difficult, and is particularly a useful addition for those wearing glasses (as I can attest to. PS. The mesh will indeed prevent your glasses from sparkling in the light and ruining the ‘invisibility’ of your costume)

Is there a reason that women tend not to wear skirts or dresses instead of pants?

Again, it’s up to your comfort and the style of performance. When my company decided to restage our first show, we made our own costumes (having initially borrowed some from uni) and instead of using black pants/top and hood, we decided to make long medieval-style dresses. They were quite stylish, not too medieval, without being ornately decorated or over-the-top. They suited the content of our play (an abstract series of short scenes), were individualised to each person but still retained an overall theme, and were of the same black fabric as our stage curtain. They were neutral enough to be worn in different shows that had different settings. (There was no hood, although we planned on adding some, cape-style) Personally, I found my custom-made dress to be just as comfortable and fitting - in a contextual sense - as wearing pants. Although it would have been nicer if we had remembered to add some pockets as well  Many female puppeteers wear short or long skirts and dresses, but I sense that pants are more common due to the decreased likelihood of having flowing clothing getting in the way of movement or getting caught on sets and props. It’s the same reason why ties are less likely to be seen in a woodworking shop; they can be dangerous for the person wearing them. (In a more realistic sense, women may avoid wearing them for reasons less practical: not wanting to deal with people looking up their skirts whilst they are in unusual positions often necessary to get the puppet in the correct place onstage) Additionally, in a mixed-gender cast, it may be an aesthetic choice to have all puppeteers wearing the same, or similar, outfits in order to decrease the contrast between each other, their puppets and their sets, making them less noticeable overall to the audience.

Other clothing suggestions:

As a puppeteer, it may be a good idea to wear cargo pants, or something with pockets. For small companies who tour, or solo performers, this is especially useful as it allows the person to wear items such as: iPods or remote controls for sound playback and/or lighting operation; props or small objects (kazoos or other instruments); cheat sheets or running orders; torches; or anything else that might be handy. I know cargo pants are terribly passe but actually they come in real handy when working in a theatrical environment, and can be just as good, or better, than wearing a toolbelt, especially when trying to create a costume that fits into the context of being visible onstage whilst still being neutral.

… I’m sure there are plenty of other things to discuss in terms of costuming for puppeteers, but that should get you started. If I’ve missed something, or you have a suggestion, leave a comment and I’ll add it to the post.