Over the years Citizen have changed their watch case back markings, whilst they have also used special backs on their high grade watches and certain specific models. This page attempts to show the basic types and how to interpret the information that case backs give – often crucial to determining the authenticity of the watch. I’ll cover special case backs on a separate page.
After the very early models using the ‘F’ type movement, Citizen began to develop a wider model range and towards the end of the 1940s and particularly in the 1950s a number of models were in production. Each of these used various case designs, with different case materials, and the case back markings began to reflect this. I have identified three core formats, and I’ll show these in the following sections, along with some of the variants that can be found – one of the joys of this for the collector is the variety of case backs that occur as result.
The late 1950s also saw the introduction of serial numbers, which are very useful to us of course, because we can determine the date of production. More on that later.
Before covering the three basic designs, a word about the very early models. Little information is stamped on the back – typically it may relate only to the case back material:
I’ll provide more information on the early case backs in a ‘Featured Watch’ post on the Type F.
Acknowledgement – in order to get a uniform type of image and size, I have primarily used the Japanese Domestic Watch volumes as a source, I wish to give due acknowledgement and credit here.
Early Case Backs:
This section relates to watches made from around 1950 to the early 1960s. During that period Citizen’s watch production accelerated enormously, particularly with the success in the domestic Japanese market of the ‘Deluxe’ hand winder. An ever wider range of hand winding watches was produced, and in 1958 Citizen launched their first automatic, soon followed by the ‘Jet’ rotored automatics of the early 1960s. Not all watches had a serial number at this time, although sometimes they may be found stamped inside the case back.
Typically the early watches use snap / press on case backs, and case type markings therefore make their appearance on the ‘transitional’ and later formats.
And not all case backs carried all the markings – some were minimally stamped and very simple whilst some were decorated, often with scrolled engraved lines. After looking at a fully marked example, I’ll show some of the variations. Here’s an example from 1963, which carries all the information to be found at that time except water resistance – see the labels for their meaning:
1) ‘STAR’ – as far as I know this the mark of Citizen’s own case factory. It is found on watches from the 1940s through to the late 1960s.
2) ‘CGP’ – this is the Case Material Code – often this is an abbreviation, and is usually self-explanatory as in this example (Citizen Gold Plate). Some gold plated and especially gold filled watches specified the thickness of the gold, in microns. Gold filled watches were also marked to show the quality of the gold used, e.g ’14K’
3) ‘Stainless Back’ – the case back material is often stamped, particularly when the case is of a different material.
4) General & Specific Model Names – in this example the general model range is Homer, which is gleaned from the movement name. This watch has a day window only, and is therefore known as a Homer ‘Weekly’. Other models also use the Homer movement, so will carry their own model name, e.g. ‘Newmaster’. Model names on the case back are more common in the early models than later pieces.
5) Model ‘Number’ – this early type of model designation which included letters and numbers (straightforward in this example) was changed in the late 1960s to a two part numerical format, i.e. 12-3456
6) Serial Number – by 1963 the use of this type of serial number was well established – see later on in the page for information on serial numbers and production dates.
7) This example has no indication of water resistance – watches were increasingly marked ‘Parawater’ after 1958 when Citizen designed water proof cases for the first time. ‘Parawater’ continued until the early 1970s when it was replaced by ‘Water Resistant’.
Variants on this format often have less information than the above illustration. First are two Center Second models from the 1950s, one with an early ‘Everbright’ back – this may be an alloy back rather than stainless steel – and one showing a 40 micron 14K gold filled case, with number only model designation (NB: center second models used that name on the dial, but other models like the Master and Junior also had center second case backs like these):
Here’s an Ace Date with serial number, and a fully marked Alarm Date with decorative scrolling- note that this one also shows water resistance – ‘Parawater’:
This earlier alarm (left) has a ‘cricket’ type back (double skin with holes to help project the sound) whilst the first automatic from 1958 uses ‘water protected’ rather than ‘Parawater’. This has a screw on type back indicated by the indentations to locate a removal tool:
Transitional Case Backs:
I’ve called the next format ‘transitional’ because they use the layout of the later case backs whilst retaining the earlier model designations. More and more watches were using screw on backs and less were using the snap on type more typical of the early model ranges. Case design was also developing and other case types were emerging. Here is an example of a fully marked ‘transitional’ screw on back:
1) The back now has a circular outer ‘track’, with markings stamped around it and other information in the centre
2) The Model Number, or designation, is in the same style as the early format, usually a mix of letter and numbers
Here are some permutations – the Autodater 7 appears to be etched rather than stamped, and (unusually) has no serial number, whilst on the Crystal 7 the model symbol fills the centre:
These original illustrations are from a 1960s technical manual – the first shows the case type as ‘GN’ with different layouts:
And here are the same with ‘OR’ designations – the same type of cases, so ‘OR’ means the same as ‘GN’ as far as I know but is less commonly seen:
Note also that two case backs (see the two on the right in the above image) are marked with an encircled ‘x’. This means these cases are one piece that have to be opened through the glass, as on this Seven:
Later Case Backs:
The end of the 1960s saw the introduction of case numbers, distinct from the earlier combined model designation. Case numbers always start with the number ‘4’, followed by a dash and six other numbers i.e 4-123456. With the new case number system, a new model number format was also instigated: 12-3456.
The case number is often more useful than the model number, since it usually includes a reference to the movement in the watch. So for example, case number 4-520343 tells us that a movement from the ’52’ family is used.
Model names are not often seen on the back, but some now indicate the movement to be found inside – this is very helpful of course!
Here’s a typical example of a fully marked back:
1) I have not been able to determine the system, if any, for model numbers – they generally do not help to identify the movement used.
2) In the above example you can see how the case number relates very clearly to the movement (7200)
3) ‘STAR’ has now been dropped, and the manufacturer’s name is more prominent. Later watches have ‘Citizen Watch Co’ rather than just ‘Citizen’
As ever, there are variations on this theme – some models, I think only in the Seven Star range, have a ‘horseshoe’ track rather than a full circle, and some backs have no model information – the X8 Cosmotron on the right is marked ‘transistorized’ reflecting the application of new technology, but is not marked ‘parawater’ or ‘water resistant’:
Some backs are simpler, with no outer ‘track’ – the Cosmotron on the right below also has a different type of case / model combined number which uses the full movement designation as its first part; it’s also now marked ‘water resistant’ and ‘electronic’ rather than transistorized’:
The Seven Star on the left below has the case number in the outer track, echoing the ‘transitional’ format, and on the right a black coated Custom V2 also has a coated back (others had stainless steel backs):
Serial Numbers and Production Dates:
Dating a vintage Citizen watch is relatively straightforward when it has a serial number on the case back. The key is knowing which decade the watch was produced in, and the Movement Table is useful for determining that.
The first three numbers in the serial are used for the date – the first number is the year. So, using the Seven Star pictured above left as an example, with a serial number of 90203597, the first number of the serial is ‘9‘ indicates the year. But which decade is it from?
The ‘Parawater’ designation means that the watch was not produced later than about 1973. The case number – 4-520068 – is in the later format, and the ’52’ movements were first made in 1965 so the watch cannot be earlier than the late 1960s. We can safely conclude from this that the watch was made in 1969.
The month is easier since Citizen used the second and third numbers in the serial to represent the month – 02 on this one means production in February.
Hopefully the information to be found on this blog will allow accurate dating of watches, but please ask if you want to check anything out, especially if your watch has no serial number or was produced across more than one decade.