I'm not sure how I missed this thread. Been very pre-occupied the last few weeks.
But NOW we're getting into my territory. To start, I'm a long time practitioner of BDSM, re-enactor and combat enthusiast, and I have my own leatherworking business. So, I come at this subject from several different directions. And to set the stage, yes, I have given MANY whippings/beatings, using all kinds of equipment. And Yes, I have received some whippings, both self-flagellation and from another person, and I've been hit with many swords/spears.clubs/etc. So...ummm...yeah.
First off, HUGE differences between BDSM play (all levels), and what is done in judicial whipings/canings. And ancient whippings done as/before execution, I would imagine to be much worse.
Second, everyone has their own pain levels, pain responses, and particular foibles. I've known people who could take a helluva whipping with flogger, cane, and even singletail, but paddles scared the hell out of them. My leather paddles were absolutely terrifying to them (and were never used). The brain is a weird thing.
Pretty much all of what has been stated by other BDSM enthusiasts holds true. Study and practice are important, safety is a huge thing, aftercare, safewords, and knowing your partner and their signs and responses...all part of it. If this is your goal, there are some wonderful books on the subjects, and nothing beats (see what I did there) meeting and talking with people in real life.
But, to get what I saw as the crux (did it again) of the post, it was really about 1) technique, and 2) response. Understanding the mechanics of a whipping.
Technique varies. For BDSM, the goal is not to cause immeasurable pain. The goal is to use pain as a transcendence tool. Is it sexual? For many people it is. But, for many, subspace can send them into a place of euphoria. This is very good, but poses it's own hazards. How one gets there is the trick.
As has been stated, it usually starts with a warm-up. Start slower, weaker, and slowly build up the pain levels. A person can take a massively painful blow well into a scene and can send them into waves of tranquility or sexual gratification. But, give that same shot at the beginning of a scene, and there will be hell to pay. That person will never want to play with you again, and you will be banished from your club.
However, if your goal was true punishment, then your goal is to cause as much pain as possible. No warm-ups. Shot selection and strength would be to cause the most pain possible. It would be very important to know where and how to strike, and what your intended purpose is. Is it to quickly cripple the person? Kill them? Make the pain last as long as possible?
Which brings us to another point: Pain endurance. Everyone has different, and different kinds, of pain levels. And those levels change, according to the situation. I once played an entire half of a soccer game (45 minute's) with a broken collarbone. My clavicle was literally pushing up through the skin. I never noticed it, because I was running on pure adrenaline and hate. Only discovered it after the game when I realized that I could not raise my arm to get my jersey off. By the same token, I have also called it day when I stubbed my little toe. That shit HURT! Slow build-ups can make that endurance greater. Massive shocks and reduce it. Rage and adrenaline, can deaden pain. Fear and trepidation can increase it. In BDSM scenes (with the right partner), I have been known to pull a sub in-and-out of pleasure, by variously building up and giving them sensations that they enjoy, and adding in shocks or things that cause fear. So, those things can be used to heighten sensations, for good or ill.
Equipment is fundamental. As another poster said, anything can be safe in the right hands. The flip side is that almost anything can be dangerous in the wrong hands. And almost anything can be used to give sensations. There are hundreds of types of floggers, singletails, crops, canes, paddles, and restraining devices. This doesn't count the new or odd things that can be used: electricity, rubber toys, fingernails, blades...I've used watch bands to great effect. The key is knowing your tools, how they can be used, and what they are capable of. A singletail laid flat across the buttocks or shoulders with the right amount of force can cause pain without real damage. In the hands of a skilled practitioner, it can be 'popped' or cracked to cause massive stinging and orgasm inducing fear. But, hit too hard, in the wrong place on the body, with the wrong part of the whip, and you can break skin, even bones, or even burst internal organs. The cracking sound you hear is the tip breaking the sound barrier. The popper is tiny, has very little mass, and is usually fluffed at the end, all of which make the force light enough to take in certain areas. Move the striking surface down a few inches...and the mass increases a hundredfold. It goes from a bee sting to being a large caliber bullet.
A flogger can be light or heavy, thuddy or stingy. They are the most common BDSM toy. You can slowly build someone up with one in a sensual ballet. But, used in another manner, it can cause intense pain,possibly break skin, and in extreme circumstances, damage the spine, throat, or kidneys. For some customers, I have created thick, soft, thuddy leathers floggers, but cut the tips to a chisel point, to give it more sting. I can take a flat, thuddy flogger that makes a nice soft thud, but throw it in a different way so that the falls do not hit at the same time, or wrap it around a body, causing the tips to speed up, and make it sting and welt on a more delicate area like the sides or belly. Pleasure or pain, endorphins or physical damage. It really depends on how you use the tool.
And the final ingredient is really psychology and body dynamics. How does your brain and body process the experience? It's somewhat different for everyone, but there are some general commonalities. Backs, chests, and legs can generally take more punishment. Shocks (physical or mental) can take away endorphines. Fear can add to pain. And everyone has breaking point before they either pass out, or their brains just 'checks out'. Controlling fear and pain is really the key regardless of whether you want the ultimate BDSM experience, or whether you want to truly torture them.
I've rambled and gone on for way too long. Sorry. I get excited about the subject matter.
There are lots of good resources. Books, people, seminars. If anyone wants to ask me about any of it, please feel free to do so, and I will happily share what knowledge and experience I have.