I vote for the finger/toe nail polish… Won’t wash off,but is temporary . Finger prints as a fail safe,in case of male first born inheritance issues.
IIRC, there an episode of “Full House” about this. I’m pretty sure Uncle Jesse and Uncle Joey got to the point of examining footprints and trying to match with the hospital birth certificates to figure it out before Aunt Becky got home.
Ah, the hijinks.
Different Haircuts?
If they have hair:smack:
Totally ripped off of a Dick Van Dyke episode.
I don’t think the ferret collar idea will work, and people will look at you strangely if you put a dog collar on your babies. Unless you’re punk rockers of some sort. 
That was my first thought as well. Nothing insane, just a dot or two on the back of a hand.
I remember an episode of My Three Sons in which this was an issue. One of the characters on that show had identical triplet sons and after the characters were confused about the identities of the babies, they took them back to the hospital to match to the footprints taken at birth. (Do they still take footprints at birth?)
My wife and I have identical triplet boys just under a year old.
One of them has always been a bit smaller than the others (currently 24 pounds vs. nearly 26), and as a result his facial features are just a bit thinner. It’s enough to see pretty quickly when you’re around them often.
The other two are much harder to distinguish - I still mess it up sometimes when I don’t recall what each kid is wearing that day. However, one of them had to have abdominal surgery when he was six days old, so we can always lift the shirt and check for the scar. But there are subtle differences in their faces; after being around them for a bit you learn to pick them up.
From the beginning, we color-coded them. Blue, green, and yellow were what we wound up using, and wardrobe tended to be based on that. Now that they’re older, we don’t adhere to it as strictly (since we’re confident we won’t get them mixed up), but it does help visitors and helpers (off topic, but we have been offered - and would have gone bonkers had we not accepted - tons of help from friends, family, and acquaintances).
“The yellow one’s” color is gently transitioning to red. I’m envisioning colored markers on a whiteboard for messages and notes in the future, and yellow-on-white sounds like a nightmare. Yellow is also difficult to find in some items, although it was originally chosen because pastels of blue, green, and yellow were the easiest non-pink colors to get for things like our preferred brand of bottle. Our six-year old daughter has enthusiastically adopted pink as her color.
Having overshot our goal by 100%, we’re well and truly done having kids; we won’t be needing any more colors in the future. 
We were reluctant to cut the bracelets off when they came home from the hospital! All spent time in the NICU and they didn’t all get discharged at the same time.
We tried painting their fingernails, but that wore off pretty quickly and we found that it wasn’t worth the effort to re-apply.
Basically, like most aspects of parenting multiples, we just figure out a way.
It’s what I was told by one of the twins.
I remember a show about multiple births in which the parents had identical quadruplet boys. I think they used clothes in the early days. By the time of the program they were nine and easy for the parents to tell them apart.
Not too much after that I saw the same kids in a Tide commercial, with the mom extolling the virtures of Tide when you have four active boys of the same age.
Can you imagine having four teenage boys eating you out of house and home?
if you take too long the skin will grow around the bracelet.
My brother and his wife painted one fingernail or toenail of their girls, IIRC. But pretty quickly once they came home, the girls started showing their personalities - and there are some slight differences in their appearance, that was evident once they were 6 months or so.
Now that they’re 6, it’s mostly easy to tell them apart (their dress choices help), but it still happens - and they absolutely tell you when you call them by the wrong name!
My twins are not identical but they were really close as newbies. Sometimes I had to look twice but I could tell them apart. Now they are aged ten, with some of the baby pictures I can’t distinguish them any longer.
That’s something I’d forgotten about. Especially in the hospital (where they spent several weeks), we have many photos of … somebody. We may have known at the time, but now it’s hopeless. I’d better start tagging pictures somehow, because the problem isn’t likely to go away.
I have no real experience with this, but naively ask: can’t you just tattoo small dots on the bottoms of their feet? 1 for first born, 2 for second, etc.? (Like the Dahm triplets mentioned above, but in a less visible place.)
J.
My sisters are identical twins, but they’re very easy for me to tell apart, even as babies. I can look at baby pictures and tell which is which. It’s not so much the facial features as the expressions.
I saw on the news that,after 8 years trying, a woman and her husband had Quadruplets … all girls,2 sets of identical twins…
That’s what my cousin did. Initial on the bottom of the left foot. Eight years later, only their sisters and parents can tell them apart. They’re amazingly similar in appearance and actions.
I used Sharpie on a set of identical albino rats not too long ago, so the petsitter could tell them apart. “The medication goes into the one with blue streaks on her back. The other two just get the food and the love.” 