Basics
So what is this bondage thing all about anyway? Webby helpfully points out that bondage is the state of being bound. Delightful!
To be a little more specific, erotic bondage is the act of using rope or other objects to restrain your partner in a display of power exchange. The submissive (or bottom) desires to relinquish freedom of some part of her life, where the Dominant (or top) desires to gain control. Bondage is not restricted to rope play; Saran Wrap, ribbons/dental floss, cages, crates, chains, vet wrap, bandages and leather cuffs/harnesses are examples of alternative bondage tools. The term bondage can probably be extended to encompass emotional/circumstantial restraint, but that's usually better labeled as mindfuck.
Since roleplay is important in most BDSM encounters, the relationships between people in a scene can become complicated. The "top" in any given scene might refer to themself as Dom/me, Daddy/Mommy or Master/Mistress, where bottom might be called a sub, slave, girl/boy or some other diminutive. Even more confusing are self-proclaimed "switches" who are not committed to either role 100% of the time, though normally one does not switch roles in the middle of a scene. It is not unheard of for a person to come out of a role as submissive and then proceed to tie someone else up, taking on a Dominant role. For this article, I'm going to use the terms "top" and "bottom" because they accurately describe the roles of each party within a typical two-party bondage scene, without making assumptions about the participants' relationship to each other. I'm also assigning our hypothetical bottom to the female gender, but this should not be taken to imply that bondage is exclusively male-dominant.
Safety
For many, bondage is "just a kink", enjoyed as a precursor to or enhancement of "normal" sexual acts. Scarves or neckties around the bedpost are a common and seemingly gentle kink. This is deceptive; all bondage comes with more or less the same set of risks. Nerve damage can result from lack of blood/oxygen supply to bound parts, especially when limbs are left elevated above heart level(bedframe, anyone?) for a sustained length of time. "Sustained" in this instance could mean anywhere from less than a minute up to many minutes or an hour, depending on the bound person's circulation and anatomy.
The risk with the scarves is compounded by the fact that silk tends to be slippery and airy, so the knots may compress very snugly on themselves, meaning that your knot could become impossible to untie. Another concern is that depending on the mental/emotional state of your bottom, she may not tell you right away if things become more uncomfortable. Around the wrists, this is bad, and could cause nerve damage in the hands, but on the off chance that someone is tied by the neck with a scarf, or somehow gets wrapped up around the neck, this activity could certainly become deadly. A bound person should never be left alone, especially if a gag or blindfold is being used.
When I travel to parties and events, I bring a big clunky toybag with the appropriate tools for a night of entertainment, but I also have a separate smaller bag that stays within arm's reach for every scene, containing a small first aid kit, and my bondage escape kit. This is just a pocket with baby oil, extra handcuff keys, a large but pointy knitting needle and crochet hook to wiggle and loosen knots, and a pair of EMT shears which can be used to cut away ropes or clothing in an emergency situation.
Negotiation
Discussing your partner's health, and personal objectives is an important part of any scene negotiation, but when bondage is involved, it is crucial. There are two widely known kink mantras out there- SSC(Safe, Sane and Consensual) and RACK(Risk Aware Consensual Kink). I prefer to evaluate scenes in terms of risk rather than what seems a rather nebulous idea of "Safety."
Determining the risks involved in a desired activity means honestly assessing yourself(skills, equipment, state of mind, level of fatigue or sleep deprivation) and your partner(experience level, history, disabilities or medical conditions, size, weight, bladder size). Since you are the top, be aware that the bottom might expect you to "handle everything," even when you are negotiating in a non-play environment. If you run into this situation, you must coax your intended partner to talk to you openly, or reconsider whether you can really play safely with them. If they can't indicate their desires and personal taboos in a relatively low energy situation, chances are they will also have difficulty if it came to a head in the middle of a scene.
The Submissive BDSM Play Partner Check List is a great tool to facilitate your talk, and can be modified to include only bondage items if that is the full extent of your encounter. Once the list is filled out, talk about why each item got a high or low score.
Purpose of Bondage
For some, the purpose of bondage differs from common vincilagnia. Often a bondage scene is done for its own sake, with no expectation of outright sexual conduct during or following the scene. Some consider bondage a means to an end, and use it to restrain someone, but find no particular pleasure in the tying itself. Other reasons for bondage without sex include improving your bondage skills/experimenting with new techniques, testing the waters with a new or potential partner, or forming an emotional but non-sexual bond with a partner. Shibari, especially, focuses on the ropework as an art form, sculpture of a living body. Ropework is one of the most widely photographed and accessible of BDSM disciplines, since it is normally pretty, and can be presented in a fairly satisfying way without depicting nudity or sex acts.
Bondage and corsetry are similar in that when designed correctly, they should fit like a tight hug around the body, not painful like a vice grip, or useless like a muumuu. Of all the standard BDSM disciplines, bondage was the first I learned, and remains my favorite. There's something very sweet and loving about even the most brutal bondage scene that flogging can't match. I enjoy the quiet patience and the connection with my partner as I gently and methodically adjust her posture. Then there's the look in her eyes when I thank her for her good behavior. Assuming she's on good behavior.
Suspension bondage is especially meditative, and the experience is closely related to sensory deprivation. This is not to say that suspensions are not normally
painful for the bottom. This is not comfortable bondage. The traditional use of rough hemp ropes for Japanese-style suspensions emphasizes the
presence of the rope itself. This can mislead the bottom's mind into forgetting that the rope is holding her up, resulting in a feeling of "heavy weightlessness". Using blindfolds and earplugs enhances this experience of sensory deprivation.
Aftercare
If your bottom is at a comfortable temperature during the scene, make sure you have a blanket or other snuggly handy for when you remove the bondage. Liberation often causes bottoms to feel cold and naked(even when relatively clothed) I suspect that this has more to do with the return of circulation and sensation than the warmth of the ropes.
It's great to have small bites of food around to help bring your bottom back to reality. Most play parties will have a bowl of grapes or small chocolates for this. Offer water, even if she is not visibly sweating or parched.
It's a good idea to discuss aftercare as part of your negototiation before the scene, but once the normal balance of power is restored, you can usually relax a little bit. Your bottom might want to be left alone for a little while, or she might come straight to you for comfort and reassurance. You can talk a little bit about the scene now, especially to thank her and tell her that she pleased you (if she did), but it's usually best to let her take this time to orient herself and enjoy the after effects. This is actually what endeared me inextricably to bondage at my first introduction. There is an intense closeness between a good bondage top and bottom after a scene. The sensation, the energy and adrenaline that come with a hot scene are pleasurable and intense, but afterwards, seratonin kicks in and you are just together, and the bottom is trusting and relieved. It's comfortable and sweet.
It's not always happy of course, because humans are not infallible, and not every situation can be predicted. The scene may have stirred thoughts or emotions that the bottom did not expect to have to deal with, so she might cry or feel fear or anger. Basically, all you can do is gently support her, and help guide her back to her normal headspace and rest of her life when she feels ready.
Equipment
Metal and Leather
To restrain someone's arms quickly, impersonally and forcefully, it is hard to deny the value of plain old handcuffs. Novelty fuzzy handcuffs (normal metal or plastic(!) cuffs, wrapped with velour) are cheap, useless and not that comfortable. I find there is high erotic value in steel- cold, unyielding and stoic. Plain metal cuffs do get mighty uncomfortable epecially for exended time periods, so if that is not your intention for the encounter, you might consider leather cuffs.
One point of trouble with both leather and metal cuffs is that a large wrist to hand diameter ratio will neatly defeat them. Some bottoms slip out of suspension cuffs without even trying, but kinky leathersmiths are always developing better cuffs, so it's worth trying lots and lots of them on for size if you get the opportunity. You can also purchase handcuff inserts to decrease the inside area of the cuff, making things more challenging for your bottom. Hinged cuffs offer an even greater obstacle. Instead of a chain, they are held together with a butterfly hinge, so that twisting the wrist becomes very painful. These are also not healthy for the bottom's wrists over extended periods, so limit their use and check in often.
Please note that cuffs and wrist ties can be very damaging to people who suffer from Carpal Tunnel Syndrome. Don't use them. And if you do, be cautious and attentive.
Bondage Rope
If you like it smooth, there is always nylon solid braid rope from your local hardware or boating store. This normally comes in a lovely shade of white. You might also be able to find a solid braid MFP(multifilament polypropylene- NOT monofilament) http://www.rainbowrope.com sells overpriced bondage rope, but they will cut it to your specifications, and carry many many gorgeous colors(hence "rainbow"), and hard to find diameters. This is great if you're trying to match an outfit, but in general, you can find similar quality at a hardware or boating supply store. Climbing rope is good for bondage because it's designed to hold human weight. It is even rated for a maximum load, for your peace of mind, but this is an expensive option.
Hemp rope is another popular option, and you do want to buy specialty bondage rope for this, as mainstream commercial hemp rope is very scratchy and not so strong. Hemp and other natural fiber rope is gaining popularity, so I'd suggest attending your local fetish convention, and shopping with your hands. People like different things from their rope, and there is no way you can judge this over the internet. Where synthetic rope is more or less the same across the board, natural fiber ropes vary a great deal in their softness, staple length, twist angle, final conditioning. Hemp rope is a hassle. If you do not find it absolutely delicious, I would recommend against trying it at first. That said, I am quite pleased with hemp rope I've purchased from http://www.twistedmonk.com/. They even sell "starter" kits containing several "traditional" lengths, and a pair of EMT shears in case you get into a bind. Some love http://www.JapanRope.com/.
Another point to keep in mind when choosing rope is how you will use it. Do you have many partners? Just one? Synthetic rope is easy to wash thoroughly in the washing machine or dishwasher, and can be soaked in a mild bleach solution if you suspect blood or fluid contact. Hemp rope needs oiling and conditioning after you wash it to keep it from drying out and fraying, and bleaching it will significantly shorten its useful life. For this reason, most people who play with hemp often have a separate set of ropes for each partner, which can get costly. Another option is to reserve the hemp for a committed partner, while using synthetic with new friends. And seriously, don't buy hemp from anyone until you've had a chance to feel it.
I recommend that you read anything by Midori for information on traditional Japanese Shibari and for a more practical approach, read Lee (Brigette) Harrington or Jay Wiseman.
Aside from the books above and assorted literature, everything I know on the subject has come from hanging out in the Boston kink scene, but I'm very curious how BDSM and bondage are evolving in other places. Also, if you see errors or inconsistencies, please call me out.
All things kink.