One of the great things about rope bondage is that you do not need a lot of expensive gear to enjoy it. At a minimum, though, you will need some rope and some kind of emergency cutting tool. $20 is plenty to get you started on your bondage career.
Rope
Although there are dozens of types of rope available, choosing rope is actually surprisingly easy. You're looking for rope that feels good against your skin, and that holds knots nicely. Beyond that, it's all a question of personal taste. To get you started, here are two popular choices.
Budget rope
The rope that we use in our classes is 1/4" (6mm) braided white nylon/polypropylene. A 100' package costs about $12 at a home improvement store. We like it because it's cheap and easy to take care of, and because it feels good on skin. It's fairly slippery, so you will find that it doesn't hold knots as well as some other materials. With any synthetic rope, make sure that you're getting braided rope rather than twisted.
To prepare your rope, measure the lengths you want and wrap duct tape around the rope at your cut points. Cut the rope in the middle of the duct tape, and you're done. Leave the tape in place so the ends don't unravel.
The good stuff: hemp rope
Most of us use hemp rope for our personal play. Hemp comes in several thicknesses, but 6mm is the best choice for beginners. Hemp rope requires considerable processing in order to be suitable for bondage. It's possible to buy raw stock and condition it yourself, but we recommend buying finished product from Twisted Monk. Raw stock will cost you about $0.60/foot; finished rope generally runs a little over $1/foot, and is well worth it.
Rope lengths
For most applications, fairly short lengths are most useful. We use 12.5' lengths in our classes, but anything between 10' and 15' will work well. You will occasionally find a use for a 30' length, especially for chest harnesses. Ropes over 30' in length are tedious to work with, and there are only a few specialized applications that call for 50' lengths. A good starter kit which you can cut from a single 100' package of rope would be four 15' lengths and one 30' length.
Washing your rope
With a little care, you can wash your rope when it gets dirty. You can wash it by hand, or in a washing machine inside a lingerie bag or pillowcase. Rope should never go in a tumble dryer: just hang it up and let it air dry.
Synthetic rope can be used as soon as it's dry. Hemp rope, however, needs to be oiled to keep it soft and flexible. You can oil your hemp with mineral oil or mink oil (from a shoe store). Pour a little into your hands and run the rope through them, being sure to spread it evenly across the whole rope. Don't go overboard: a little goes a long way.
Cutting tools
We consider an emergency cutting tool to be mandatory gear for any rope bondage scene. If you need to get someone out of bondage in a hurry, you need a cutting tool that can reliably cut rope without cutting your partner. Cutting rope can be harder than it looks -- make sure that you practice before you find yourself in an emergency situation.
EMT shears
EMT shears are inexpensive (about $5) and very effective for cutting through rope, leather, and clothes. They are specially designed for cutting next to skin without injury. You can get them at drugstores, army surplus stores, and marine hardware stores. We particularly like the titanium coated EMT shears made by Clauss.
Rescue hooks
Rescue hooks are more expensive than shears, but they cut amazingly well and some people find them easier to use than shears. The Benchmade Model 5 is a popular choice.
Knives
We love knives, but they are not suitable for cutting someone out of bondage in an emergency. It is almost impossible to get a sharp knife between skin and rope without cutting your partner.