I wear detachable collars a couple times a week - some vintage (restored), but most a brand-new, made in the UK (you can order them online), and with modern manufacturing they don't need to be as stiff as a board. Some versions can even be thrown in the laundry and ironed.

I find they're great for business travel. Pack 1-2 collarless shirts with 3-4 collars (make sure they're different styles), and you're set for a week. It does make a difference when packing.

In Sweden these collars were called "Fadermördare" -- "Father Killers"!

Collars could be either disposable or reusable. The disposables were cheap, usually paper/cardboard and came in at around 25-50 cents per dozen. They could be worn either once or a few times and then used for kindling in the stove. The reusables were obviously more expensive depending on the style and material. Linen, cloth/cotton, celluloid (an early synthetic material) were all more or less popular in different eras and for different seasons of the year. Some collars were made of rubber and advertised as "water-proof". You could get soft or stiff starched collars (with or without a sheen to them) and in a myriad of styles and heights. Really, the possibilities were endless as compared to the collar choices available to men today. Detachable collars literally reached their "height" of popularity circa 1900, when 3-inch stand-up collars were the rage. By the date of this photo detachables were already starting to fade away for everyday wear. As you may have guessed, I am a detachable collar affectionado aficionado and am anxiously awaiting their revival (but I'm not holding my breath)!

doesn't that make them only "half-a-quarter" sizes?

There were a number of benefits. You could starch the collar to stiffen it without affecting the rest of the shirt, you could have a variety of collars - in terms of styles - while having relatively few shirts which were more expensive than the collars. It was undoubtedly easier to wash the collars separately from the shirt. If the shirt or the collar wore out you didn't lose the portion that was still serviceable. It was stylish in that your collar was usually made of different material from the rest of your shirt, and of course there was always the idea of disposable collars.

They're still used today, mainly for formal wear and for special uses, like the collars for British and Canadian lawyers or for some private schools like Eton.

My father's hand laundry, the Euclid Laundry, at 260 west 86th Street, in Manhattan, would wash a collar for either 5 or 10¢. They were not disposable but would be sent in with the shirts. It would not be unusual for a bundle of laundry to contain 6 collarless shirts and a dozen collars. In the pre-air-conditioned days (like the first half of the 20th Century),
a man in an office would change his collar once or twice a day because they were soiled or wilted.

You get a fairly wrinkle resistant shirt, the attach cheap clean collars, that always looked pressed, and never get the ring around the collar problem with your shirts.

Yes, they were scrubbed, bleached and starched. Men whose collars were shabby or floppy were pitied because obviously their wives didn't care about their appearances, or their laundress was a drunk.

Since they were originally made with paper, they were detachable so the shirts could be washed. Once the collar became too grubby, one got a new one. Eventually celluloid replaced the paper and they were more durable than the shirts. Washing a shirt entailed scrubbing it - often in boiling water with bluing (to make the shirt look whiter), running it through a mangle, the shirt and the collar had to be washed separately.

These collars were a great time-saver for busy housewives. It would be possible to get several days wear out of a shirt before washing, just by changing to a fresh collar every day. Collars were easier to wash than an entire shirt, and you could starch the heck out of them. (Stiff collars were all the rage back then.) It was also cheaper to replace a worn collar than an entire shirt, as some of those early washing machines were hard on clothing. I have packed away some very starched collars that belonged to my grandfather, who was born in 1886. They are still stiff as a board to this day. The shirts they belonged to are long gone.

What's the plot with detachable collars -- do you throw them away when they get grubby? Are they washable, ironable? My wife won't iron my shirts -- would she at least do the collars?

Around 750. There seem to be 10 collars in a bundle, and around 75 collar bundles. Assuming that the boxes are empty.

A clever promotion to collar some customers.

Which collar would go best with a T-shirt? (Sort of like asking which wine to serve with hot dogs).