
It seems to me like it’s almost impossible to buy a bridle without a flash attachment any more, especially a dressage bridle. I guess I’m dating myself, because I have a clear memory of when the opposite was true: the flash was a piece of equipment you added if it were needed, but most horses did without. Now it seems like a fashion accessory
In fact, “way back when” we mostly used drop nosebands (which fell out of fashionable favor sometime when the ice age was receding). Apparently they are ugly.
I wouldn’t have a real problem with the flash noseband except for so many people don’t fit it correctly. I think people forget that the idea behind the flash was to help stabilize the jaw and keep the bit from slipping down. You are not supposed to cinch it so tight that it leaves marks on your horse’s muzzle!

Most often I see flash nosebands (and also figure 8 bridles) adjusted so they are too low — when this happens they can interfere with your horse’s breathing.
To adjust them correctly you need to start by having the cavesson adjusted so that the noseband sits 1-2 fingers below your horse’s cheekbone.
Then adjust the flash strap so that is snug but so you can still fit two fingers under the horse’s jaw.
When a flash strap is too low, or cranked too tight, they exert continuous pressure over the sinus area and can even cause nerve damage.
Flash nosebands can be helpful — I’ve used them on occasion when I had a horse that was opening its mouth and bracing against the bit — but they are not a substitute for training. True relaxation and acceptance of the bit cannot be achieved by strapping your horse’s mouth shut; often resistance in the mouth is caused by the rider.
So if you have to use a flash, make sure that’s adjusted in a way that won’t hinder your horse and think about what you want to accomplish by adding it to your bridle.
I gave up on flashes a long time ago. When I first started taking real dressage lessons with real dressage instructors they all recommended a flash. I could never adjust it so that I liked it. Too high, too low, too tight, too loose and the worst was when it pulled the cavesson out of place so that it didn’t ride correctly. I have also never seen one that seem to accomplish anything unless it was really tight and then that gets the horse’s mind on the really tight band. I had a student who had a green TB that cocked his head and set his jaw as a resistance. A figure 8, adjusted correctly, worked. It didn’t ‘hold’ his jaw in place, it was just a reminder to stop doing that.
That worked better but I can’t see a figure 8 on a dressage horse – probably not legal.
And just FYI – Passier makes bridles with removable flashes – the whole thing comes off, not just the strap. I had my eye on one but now I want a Micklem.
I learned something new. I didn’t know the real purpose of the flash was to stabilize the jaw. Most of the time I’ve heard “It’s to keep the mouth shut”.
I took the flash off my bridle because it isn’t necessary for Hudson. (For that matter, neither is a cavesson, he wears it as a fashion accessory). I dislike the flash in general. I rubbed more sore noses and under-jaw areas than I can count. I’m not against them in the right hands. I do think a lot of us would need training in proper fitting and use. (In my case, it would probably be useless, because it would be too loose. Not good either!)
i am deciding to use a flash or not i just got my mare 3 months ago and have been riding with just a reg bridal and a bit ! but all her old owners have used a flash and ive noticed a bit of grinding and going on the four hand so i am trying to decide as i dont know much about the flash ? what should i do ?
Teeth grinding is often a sign of anxiety, although it can also become a habit. I don’t like to use the flash as a way to tie a horse’s mouth shut; it’s better used to help keep the bit stable in their mouths. If I were you, I would work on getting your mare to relax and take an even contact with the bit. You don’t say what type of bit you’re using but different horses prefer different bits. If you are using a fixed ring bit like a Dee or a full cheek, why not try a loose ring? The other thing to concentrate on is moving forward. Forward solves a lot of problems. Don’t worry about her mouth, concentrate on engaging her hind end. Do you have a trainer?
i have her in a happy mouth french link d ring and yes i have a off and on trainer she has awlays done this and i am trying to be as humane as possible i like to just have the basic tack type thing and just stay natural and simple but i am just getting her better she was lame for a month she does have problems in the hind i just thought of doing it as a reimender for a bit to tell her its ok to use her backend