Actually, you’re both right - it’s dependent upon the effect one is going for. To discourage struggling, one uses a tempered steel, double-locking cuff. To give a more comfortable (but potentially less secure) restraint, one uses a solid leather or other suitable material cuff small enough to fit the wrist snugly.
I dunno; they make some pretty freakin’ soft ropes these days – a half-inch in diameter, but “whisper soft”.
Adding an element of “You will not be subjected to rope burn, but there is just no way you’re getting loose”. 
:eek:
Not to mention that they’re more dangerous. Real cuffs can lock so that they don’t either spring loose or close down. Roll over a pair of cheapies and you could ratchet the darn things down on your wrists hard enough to cause nerve or ligament damage. Rope is probably just as fun, about as cheap, and a lot safer.
Overly technical, overly serious reply (;)):
Those “whisper soft” ropes are usually fine-grain nylon, polypropylene, or another braided synthetic fiber. Cotton is fairly hard to come by, and silk damn near impossible at anything less than $3 - $5 / ft. That being the case, the softer ropes are actually easier to give a rope burn with than the slightly harsher (for example, good bondage-grade hemp), because of the lower burn speed of plastic. (I don’t know how much you know about rope work generally, but burn speed is essentially how fast you have to slide rope across someone’s skin before it will burn. Plastics have a much lower burn speed than most natural fibers, hence it’s easier to give a rope burn with them.)
I wonder if you may be talking about regular rope marks, instead of burns - where simply the pressure of the rope against the skin leaves indentations (and, in extreme cases, bruising). If that’s what you’re referring to - yes, the soft ropes will compress more before they start to compress flesh instead of their own form. However, as with all rope work, it’s essential to remember that there’s always some give in the material, as well as in the subject - it’s very hard to put someone in a bind that they cannot eventually escape, without the position or tie becoming actively painful very quickly.
Sleel - excellent point about making sure your cuffs are double-locking. My inner safety geek pushes me to say, though, that rope can be just as dangerous, if used poorly. The nerve and ligament damage is more insidious, and requires more time, but it just as great a risk - particularly in easily damaged, often tied places like wrists.
Good point. You should always check to make sure ropes aren’t too tight and haven’t tightened down more. Check circulation often, every few minutes or so, and have a pair of paramedic scissors handy to cut your partner out if you need him or her out of bondage right now. That’s another reason that (despite having to learn knots and be more vigilant) ropes are probably a bit safer for most people; you can get rid of them in seconds with scissors. Metal cuffs, on the other hand…
An intriguing concept, but still no substitute for toilet training.
Oh, that explains it.
Seriously, I wander into some of these threads and come away with more questions (that I’m not sure I want answered) than answers. 
:eek:
You’re welcome. 