Any disruption of the interference fit between the contact or cutting faces can ruin scissors - it's a lot like grinding a straight razor, but where you have incredibly strict angle requirements across a compound surface. You're absolutely right though that the #1 mistake people make is to mess up the hollows by flat sharpening them like knives.
Sharpen the angled side at the proper angle, and remove the burr by flattening the smooth side of the blade on a decent diamond stone.
I have my great grandfathers barber’s shears, and that’s how they’ve been sharpened for going on 100 years now. You need a stone wide enough for the whole blade, so that its uniformly flat, but other than that it’s pretty logical how they need to be sharpened.
It's a shame more fabric enthusiastics don't do this, we'd have an army of skilled blade sharpeners and weapon/fabric enthusiastics could join forces and reign supreme
I think everyone should learn how to sharpen a kitchen knife at least.
Dull knives are dangerous, and it really only takes an afternoon to get decent at sharpening a knife.
Unfortunately there’s a lot of lore about knife sharpening, like how you need really fine grit stones, or a whetstone being the best, when in reality you can get a shaving sharp edge from a 20 dollar diamond stone from a hardware store. Sure, a 4000 grit stone will get you a mirror finish and a more refined edge that will last slightly longer, but even an 80 grit stone when used properly, will get you a good edge that will last for months without any other sharpening.
I think it's down to most people not having used modern high end shears, which usually have convex bevels (and some pain in the ass exotic steels). If you can sharpen that without destroying the tension/edge finish using a hardware store stone (like someone in this thread was claiming), I'll be properly impressed.
Yeah maybe with a belt sharpener, but I just use my stone. I guess my scissors have a flat bevel. It never occurred to me anyone would put a convex edge on a pair of scissors. Unless you're talking about how the blades bend inwards slightly, in which case, I haven't had any issues getting my scissors back to fabric-sharp.
That single (or doubled) convex blade profile is the big defining difference between shears and scissors. There's some other things like grip sizes and thickness of the blades relative to each other that separate things like tailoring shears and dressmaking shears, but those aren't nearly as codified. And that's ignoring all the complexities you get with beauty shears, or the absolute hell that is trying to sharpen pinking or thinning shears, especially if the inner blade has a nick in it that requires reprofiling. Its fascinating how complex such simple tools have become as we've adapted them for ever more specialized tasks!