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Eames Shell Cincinatti manufacture date

- 03 Nov 2013 -
32 posts / 0 new

Hi, Okay, to update, I know the chair with the 'C' was manufactured in Cincinatti. Anyone know when chair manufacturing there started/stopped? I am on the look out for a LAX chair and just looking into the markings/stamps/stickers on Eames chairs. I know there is a lot of history behind these and also a lot of variations. I will narrow this down to one variation here to keep things short. I have seen a chair with the Herman Miller 'H' logo with a circle with an 'S' inside and one with the Herman Miller 'H' with a cresent and 3 prong 'X' inside. Could someone shed some light on why the difference? Is it a good indication of when it was produced or where it was made? Many thanks, C I am going to try and get a one stop, comprehensive quide started soon, but this is just for my own curiosity as I am looking to purchase a chair so as much information as possible would be great.



- 03 Nov 2013

its all full of....
Its all full of overlaps, contradictions and generalizations (and I know its all been gone over countless times before, but maybe I will learn something if do a run through...)

C = Milicron Cincinnati c. 1960s - unsure for how long

Circle "S" w "Herman Miller" embossed = later Summit c. 1960s to at least mid 1970s (many of these also have paper label and HM medallion)

2 triangles ONLY = earlier Summit 1955 ish to 1959 ish, (and usually has no other markings, or just the H with no "herman miller")

3 embossed dots and no other markings = 3rd gen Zenith, possibly 1954-1956ish ... dots are found dead center between 4 shock mounts

No markings whatsoever = 2nd generation Zenith (Venice CA studio) 52-54ish (but some of these had or may still have red Venice clear labels)

No markings on Rope edge chairs, usually just the checkerboard Zenith label.

Foot glides and bases are another indicator. But it gets choppy, as bases can be switched, so look for original mount impressions on the shock mounts. And it depends on the chair type.
Dates are not hard, so these are only generalizations, and there is a lot of overlapping and transitional combinations to be found.

Arm shell foot glides and bases go something like this...

Domes of silence glides: 1949-50 Rope edged Zenith shells on X bases (start date unclear)
Boot glides unsure of start date, but go up to 1954 at least, but possibly 1955 or 1956 still used
Earliest solid H bases start as early as 55 or 56, but mostly 57 ish.
Metal swivel glides introduced in 1955-56, even 54 possibly, but also sometimes found on 1957 chairs
White plastic glides intro'd in 1957 onward

And then there are the paper labels and medallions.

smaller earlier "patent number" paper labels as early as 1954-56 ish (unclear)
larger later white "patent number" paper labels 1955 onward thru 1980s
Herman Miller round metal white Medallion: at least as early as 1959 on armshells, and through the 70s, (associated with contract only and large orders for public spaces ? )


(I have made my own list of this stuff, and it is always getting tweaked with each new sighting or piece of contradictory information....) I'm all for starting a "once and for all" list too.

PS: You know what I HATE? Misinformation. But its not easy, so excuse me if any of this sounds like total crap!

(Like that whole "dime in the mold" nonsense. I've seen the "dime" imprint on Venice chairs as well as Zenith chairs, so its not proof of "first run" of anything, as so many were touting on ebay awhile back. Its simply an early fabrication mark, and may at some point be narrowed down to a specific location or press. It is clearly a subtle fabrication mark, not a "dime" imprint. If it was just someone sticking a dime into the mold to release air, it wouldn't be so consistent every time.

Hope this helps.

- 03 Nov 2013

That's fantastic EamesHead....
That's fantastic EamesHead. Very useful info. One piece of information that I have always searched for is the date that Cincinatti ending production of the chairs. At least with Zenith, Vitra etc we know between what years a chair may have been produced, then there are the labels, shockmounts and other subtleties that can narrow the production date even further.

- 03 Nov 2013

Yeah hard to find anything on Milicron end date...
Is there a reason you are you aiming for a Milicron chair in particular?

For instance, maybe you live near the old plant and its a home town nostalgia kind of thing?

Or do you have some other shells or bases that are "correct" with that time frame?

One other thing I might mention about Milicron armshells is that sometimes (not always) there is a "waffle" pattern on the outside (reverse) of the shell that I have never seen on any other shells. (Perhaps this only appears on the early or late Milicron shells, and at some point we may be able to use it to refine dates further)

I will keep looking for an end date clue. Seems like they possibly went right up through the late 80s, but that is just a guess.

- 03 Nov 2013

Waffle pattern
Seems to be only on certain colors, and only on the arm shells.

- 03 Nov 2013

Thanks again. Not looking...
Thanks again. Not looking for a Cincinatti one at all. I just see chairs coming onto the market and I want to gauge the price and part of that would be the dating. To have best, most accurate information information possible will help decide a price to pay for a particular chair. I have see a Cincinatti chair and the price is very similar to another few I have seen which have more information about the date of manufacture ie They have a label. The chair is in great condition but if they were still manufacturing up until the mid 80s I don't think the price is really good.

I have also noted 2 variations of the Cincinatti Milicron raised logo/stamp. They both have the 'C' but the stars are different. One has this star and the other has this

I have some information regarding the glides form stating that "in Herman Miller production, I can tell you that the glides of some of the shell chairs changed four times between 1950 and 1957."

So many variations! I am determined to get an accurate timeline :-)

- 03 Nov 2013

That's impressive, EamesHead.
You are such a knowledgeable member of this forum...and sometimes you make me laugh.


Aunt Mark

- 04 Nov 2013

and lets not forget the stamps...
such as the round stamped "Summit Prime", "AX", the big "Z", etc, and date stamped chairs with the actual day of the year... (often on the paper label chairs from 57 onward)

AND numerous other embossed marks I didn't mention earlier, like the rare small backwards "Z" (or zig-zaggy "S") in the center of those three small dots sometimes... and the embossed "cartoon flame"...

But much of this stuff makes little or no difference in value... at least YET.
Color can make a huge difference in price, and of course condition.

I guess large mount chairs (Zenith rope and "Venice" no rope) are one major line to draw in the sand, value wise.

Also, the "three dot" shells sometimes have the look and feel of Venice shells, and are most often found with small mounts, but I have found a three dot shell with large mounts as well. Bases get interesting around the three dot time as well.

Hey MARK thanks! (Just a little too OCD on the fun stuff I guess.) I know I have sunk more than my share of threads with my bad haikus, so I have to actually contribute something to the forum once in awhile, right?

And WOODY, yes, I have seen only Elephant Hide Grey and Red shells with the dryish looking waffle pattern on the reverse. Sometimes very pronounced, but often not that noticeable. Have you seen other colors? Blue or black comes to mind... but cant remember ...

- 04 Nov 2013

..... ....... .....
sank a thread? chance
that you're a thread
evil in the womb.


Aunt Mark, serial fool

- 04 Nov 2013

I have seen it on red, blue, black, Ochre Dark. I wonder if it was a more prevalent issue during certain production year(s).

- 04 Nov 2013

That seems a reasonable assumption, as quality-control measures would probably kick in at some point. Could be just one molding machine for one year... or maybe the mixture of ingredients?

I will never NOT notice time frames or dates on the waffle shells ever again!

- 05 Nov 2013

Okay. So I contacted Herman...
Okay. So I contacted Herman Miller who basically told me I should go to an antique dealer and they don't have any records. Sent me a list of what previous employees remember but to be honest after trawling images of shell chairs with date stamps alot of that didn't bear true. The latest manufacture of Cincinatti shell that I have seen is dated 1977 but I am sure they go up to at least 1984.

- 06 Nov 2013


It's fun.

And there are at least two people here who would like to know.

We sometimes don't know what bits of information might become valuable or link up with other bits of information to provide context later on.

- 06 Nov 2013

Very true EamesHead. After...
Very true EamesHead. After contacting requesting information on dating a shell/chair they stated that they would actually like images and factual information regarding the manufacturing dates of chairs for their encyclopaedia.

I am going to build a web form for collecting such information. Maybe you could be of help, as I need to define, from the outset the information needs to collected.

The form will have image upload functionality and to keep things consistent I will provide image examples to people can take photos of their chairs from the same angles to keep the final information consistent and keep quality high. The images I was thinking are:

1. Of the chair as a whole
2. Of the underside of the chair to capture the markings/dates.
3. Of the shock mounts
4. Of the base
5. Of the feet ie H frame glides etc

Any others you think would need added to help ?

I also though a text field to add extra information such as when, where it was purchase, any history/provinence.

Also a field to enter contact details should something else be required.

What do you think?


- 06 Nov 2013

Sounds like you're ....
... thinking along the lines of the "eamesdesigns" seating page format?

Some thoughts..

I might add a close-up of the underside of chairs. If you are looking for true visual "evidence", some of the embossments and markings wont show up on a whole-chair underside shot.

If the online form is image based ONLY, it might weed out quite a few people who would otherwise contribute information. (I look no further than my own laziness about providing photos to know this!)

You sound like you are not afraid of real work! Very ambitious project you propose...

My own idea for a "once and for all" information list was perhaps more casual, such as a simple "time-line" thread, with a first post (like the list that I posted above)

As knowledgeable members of the forum chimed in with contradictory bits of info, I (or someone) could edit/update the list to reflect, fine-tune or expand inclusive dates.

Just a timeline really.

In this scenario, visual examples of each label or mark type could be added later. ( But I do see how there would be a need for PROOF of combinations of labels and dates etc. though..) But still, I feel that 95% of this stuff could be based on text. (and honesty)

Also, I was just zeroing in on arm shells, and maybe side shells. Perhaps that is far more narrow than your plan? (thinking of the Eamesdesigns site again..)

I'm sure BOTH versions or some combination would be useful. Are you thinking it would all just get absorbed into the eamesdesign site at some point?

- 08 Nov 2013

Thanks for the feedback...
Thanks for the feedback EamesHead.

I was thinking of just keeping it to the shell chairs (Arm, Side, Upholdstered/Non-Upholstered). This is because my main personal interest lies with these. I'm sure at a later date I could expand on that.

Good idea about the close-ups. I will make the main ones required form fields including at least one close up of the markings. Spare image fields will be there in case anything else significant appears on the chair.

As far as working it with the Eames Designs site, I think they would find it invaluable and will share the information freely and be of any help I can. There consistency of photography is great. Excellent quality control. I'm not sure what photos we will end up with on the website :-)

There will be an optional email address I think or a check box asking if the user minds being contacted by myself or if the information is to be passed on to the thrid party (Eames Designs ONLY). Have to think about that one a bit more.

All in all, it will be an interesting project. I will hopefully start within the next couple of weeks and will keep you posted.

If you or anyone else can think of other ideas regarding what to do with the information that would be great. I want to keep the form simple and quick to fill out. People are very busy :-)

- 09 Nov 2013

Glad you have a lot of extra...
Glad you have a lot of extra time on your hands.
Did the Eames office tell you these are just inventory marks on the bottom of the chair?
Did they tell you that this information has been in the public domain for years.

- 09 Nov 2013

Well...if you mean the...
Well...if you mean the information is on the public domain as in having to trawl the internet to gain some sense of when a chair was, 'possibly' manufactured, then yes that is true. There is no, 'one stop' place for a newbie to find this information ie Images, Advice on buying chairs, Dating, History, Provinence etc

Straight from Eames Office...
"At most, you can say in which ten to twenty year period a particular part was made, because that's how long a run of shells would last, sometimes longer."

"Shells were made in quantity, and stored until individual orders came in for a particular model of chair."

"Often, year to year, different options were offered as reflected by the bases."

I just want to inform someone who is new to the chairs and wishing to purchase one. That information is not readily available in one place and you can waste many hours/days researching.

Eames Office document the American Manufactured chairs quite well but require help with the European ones.

"For example, in Herman Miller production, I can tell you that the glides of some of the shell chairs changed four times between 1950 and 1957."

If that information is going to help someone, then documenting it and making it available in one place is the best possible way.

- 09 Nov 2013

Much of the information you seek has been discussed and documented in various threads on this site. It could just be a matter of organizing that info into a more cohesive and simple format, in my opinion.

(Right now, it's not exactly "one-stop shopping" for info, I will grant you that, but much of it is there)

Many of the inclusive dates, are very well known by the design community at this point, but fine-tuning them any further than in my post above becomes a matter of educated guessing.

For example, the chair glides and bases info that you mentioned, I posted in my first entry on this thread, and that is pretty close to as good as you're gonna find (with a few possible refinements and arguments, of course)

It is also known that Herman Miller employees are often not good sources when it comes to historical details. This site is much better. But stuff gets buried and is often poorly categorized. When it comes to details, you often have to search for answers.

Eamesdesign site has good info too.

You are right that there is a need for more easily accessible info of this nature. It would be a good thing to have, and would eventually help to chip away at the many "grey areas" that persist.

Sounds like you are on a learning curve, so it is important to note that even when the hundreds of details are banked, there will STILL be a lack of absolute dates in many areas. (Again, my second post above reflects what is generally known, but also reflects the vagaries that may always exist)

(These persistent and specific grey areas are also quite well known-and even legendary- among Eames design fanatics)

Hope this helps.

- 09 Nov 2013

Cheers EamesHead. I'm...
Cheers EamesHead. I'm plodding on and will let you know how things progress.

- 10 Nov 2013

I have a parchment sideshell...
I have a parchment sideshell and the only marking is the Herman Miller "H" logo. Any ideas?

- 10 Nov 2013

I would suggest opening a...
I would suggest opening a new thread for your query with pictures and much more information ;-)

Photos are worth a thousand words although if you have provinence all the better.

- 10 Nov 2013

side shell with H only... probably pre 1960.

Any info on the base? It would help. (i.e. white plastic glides on a generic H base would make it after 1957) Or was it on a swivel base?

That said, I am not as sure of dating on side shells.

- 11 Nov 2013

The "H" marked sideshell...
The "H" marked sideshell came with a dining height H base with no glides. The original glides must have been damaged because they were taken off. I'm currently using a replacement set from Hume. This one is super fibery.

I also have another parchment sideshell and an orange sideshell. Both have:
1) C with star inside (Milicron Cincinnati)
2) "H" logo with "Herman Miller" underneath
3) Paper labels

The second parchment also has a white circular "Designed by Charles Eames..." medallion sticker. No bases came with these two sideshells.

- 24 May 2014

Adding to this catalogue of markings
I have 4 shell chairs on swivels with the herman miller embossment but also a strange double flame that i've seen a handful of postings online but no substantial information. Does this ring a bell for anyone?

- 25 May 2014

THREE flames threads and no answers
What would Lunchbox say?

What would Jesus do?

Mark would _____ ___ _____.

- 01 Dec 2015

Herman Miller logo with a B & Z?

Sorry to dig up an old thread but I've hit a road block with my own research.

I just picked up this parchment sideshell and have never seen this embossed 'B' before, any thoughts?

If my research is correct, the embossed 'HERMAN MILLER' didn't start until 1960.
The chair also came with an H base w/ white nylon/plastic glides, which didn't start until '57 (assuming they're original).

Do the markings on the shock mounts mean anything? Thanks in advance.

- 06 Jul 2016

NOTE: It only took me 24 hours to realize I still had wrong information about the shells, so this post has been corrected.

Just ran across this old thread and want to thank everyone for all the information - some of which is new to me. I live in West Michigan, have purchased and sold a lot of shell chairs and have known HM employees, but it has still been tricky to find accurate information due to the company's 20+ year lack of record keeping back in the 50's-70's. I know a lot of people who would love to have a comprehensive timeline of the shell chairs and their various manufacturers. I'd like to add just a couple of pieces of information/corrections to what's already been said.

1. According to the Eames Office website, the overlapping triangles on shell chairs refer to the General American Transportation Corporation (GATC) - one of the first three makers of the shell. This is the only reference I've ever seen to yet another shell producer and would mean that none of the Summit companies had anything to do with the shells with triangles.

2. There appears to be two different Summit companies, or perhaps the same company with two different names and owners. One is Summit Prime, I've seen chairs produced in the early 60's with this stamp, and patent numbers from 1963-64. Then there are chairs with a stamp that just says "Summit", with a design that appears to approximate part of a plastic injection molding machine. Then there are chairs with an "S" or "S" in a circle. These appear to have been produced by Summit Polymers in Portage, Michigan. Summit Polymers was founded in 1972 by my former neighbor, I don't know if he purchased one of the older Summit companies and renamed it, or if it's just coincidence.

- 09 Jul 2016

For what it's worth, I can offer a few things that I have personally observed re the shells known as "Summit":

I have multiple shells with the overlapping embossed triangles.

There are 2 different varieties of overlapping embossed triangles:

The (earliest) SMALLER double triangles.
The (later) LARGER double triangles (which also bear the circled "S" embossment.

Several of my shells with SMALLER overlapping embossed triangles bear white paper labels with patent numbers that support a manufacture date as early as 1955-56 to 1958 in most cases. I also have other small double triangles shells that are from 1959 with dates clearly stamped "Aug 1959" and "Nov 3, 1959" along with the paper labels with patent numbers that support this time frame. (The original bases on these shells also support these time frames)

So clearly, there were double triangle shells being produced as early as 1956.

It was my understanding that the circled "S" embossment began in around 1960. I have no labels to pinpoint this start date, but base styles, HM medallions, and tons of other evidence has supported this over several years of cross referencing.

I do have two black shells with the circle "S" embossment that are date stamped "1974" (as your information would support) But it is widely known that the color black (BK) was first introduced by HM in 1964, and I have never seen a black shell without the circle "S" embossment on it.

So because of the info above, my guess is still that the circle "S" embossment did indeed start in around 1960 or so.

I love it when new information throws a wrench into what was known before. But each new bit of info must be cross-referenced with ALL previously established info, to be understood.

One guy saying something on the Eames design website does not make it the new "true".

As we have all learned, there are lots of seemingly conflicting bits of information about dates and places and companies that have come to light over the years. Like you said, Herman Miller let things go for 20 years or more without ANY documentation, so to me, this info on the Eames site is just one more bit to be considered and questioned with all the rest that is out there.

I hope this helps, and thanks for all of your info! (Great to get a personal angle too!)

- 26 Jan 2018


I've visited already quite some sites and it is difficult to identify an original RAR eames chair. Above is very clear and shows that there is a lot of interes in these...
Now I am looking to purchase one myself, i found one but i'm not sure if it's an original.
If anyone would know it would be highly appreciated.

Kind regards,

- 27 Jan 2018

Hi Pieter,

Herman Miller furniture was produced in Europe by Vitra for around 25 years. Your chair looks legitimate, and I'm wondering if the embossed "V" stands for Vitra? I am not able to confirm that Vitra used the "V", but I have never seen a vintage HM fiberglass shell chair produced here in the States with a "V".

I have occasionally seen Vitra items for sale here in the States too, but there would obviously be more for sale in Europe. The black rectangular HM tag on this chair was in use from 1971 to 1991, but I believe Vitra only produced items for Herman Miller from the late 1950s until the mid-1980s, after which point they directly acquired the rights to produce Eames and Nelson furniture in Europe and the Middle East. If this is a Vitra/Herman Miller armshell, it would have been produced from 1971 to 1984. (Although Vitra continued to make the fiberglass shell chairs until 1993, the chair wouldn't have the HM tag unless it was made before 1985.) I hope this was of some help!


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