US Pressing Plant Markings

On this page I'll try and unravel some of the markings that appear within the "deadwax" or "run-out groove" sections on US 60's discs. These numbers and letters can reveal the date the disc was manufactured and/or mastered and by whom and where! This will be an on-going project, so all additional information is welcome.

First up, here's a quick "rule of thumb" disc-dating grid covering five major labels and the infamous West Coast based Monarch pressing plant. Further breakdowns and explanations follow this grid:

Atlantic Records

As an example, Vala Reegan's "Fireman" has 45-6412 on the right hand side of the label, and 66C-10117 on the left. So does that make it a 64 or a 66 record? Atlantic simply used a mastering system that puts the last two digits of the year before the tape master number, thus 66C denotes a 1966 mastering for Vala's "Fire man". The master number is 10117 whilst the label number is 6412.  The "45" is simply for the speed of the record.  From January 1967 a pressing plant code was added to the master numbers:

AR:                              Allied Record Company - Los Angeles, California 
BW:                            Bestway Products - Mountainside, New Jersey 
CL:                              Columbia 
CP /  no code:        Columbia - Pitman, New Jersey 
CT / CTH:                Columbia - Terra Haute, Indiana 
LY:                                Shelley Products - Huntington Station, New York       
MO:                            Monarch Records - Los Angeles, California 
PL:                               Plastic Products - Memphis, Tennessee 
PR:                               Presswell Company - Ancora, New Jersey 
RI:                                PRC Recording Industry Products - Richmond, Indiana 
SP:                               Specialty Records Corporation - Olyphant, Pennsylvania 
WM:                           Midwest Record Pressings - Chicago, Illinois 

Capitol Records

Found extensively on the Capitol, Tower and Uptown labels, the markings of the Capitol pressing plants are either of the following:

Triangle: 
machine stamp in the deadwax containing I,A and M is for Scranton, PN.
Starburst or Daisy: 
machine stamp * asterix  * shape, is for California pressing plants.
O: machine stamped into t
he deadwax is for Jacksonville, Illinois.
Hyphen and Triangle: 
machine stamped into the deadwax for Winchester, Virginia.
R: etched into the deadwax followed by a 3 or 4 digit number for some Uptown releases, pressed by Rainbo.

The Scranton triangle is located on the label and machine stamped in the deadwax, as a two digit letter prefix, followed by a series master number of usually 3 or 4 digits. The first letter prefix code indicates the year of release the second, B, is constant, though note the letters "S" and "V" were not used in this coding system, and stereo masters had an "S" added on (i.e. SYB, SAAB):

Columbia Records

As with RCA and Capitol, Columbia's pressing plants and mastering services were utilised by plenty of smaller independent local labels. There were several pressing plants operating during the 1960s:
​Bridgeport, Connecticut: 1920s to 1964 - a CLB, or a dot next to the matrix.

Hollywood, California: 1948 to 1963 - H/HH etched in runout.

Pitman, New Jersey: 1961 to 1988 - label codes in the deadwax, inc. Atlantic CP, London P, and  Columbia P.

Santa Maria, California: 1963 to 1981 - label codes in the deadwax, inc. A&M Z, Mercury/Polydor 25, for Columbia backwards S;  Atlantic CS/CSMLondon SM.

Terre Haute, Indiana: 1953 to 1982: label codes inc. A&M Records Y/y,
 Mercury/Polydor 73; Atlantic CT/CTH; London TH;  deadwax marking is a T.

Their classic matrix codes were:

ZTSC:  Chicago (Z - indicates a 7" medium |  T - transcription |  S - indicates 45rpm | C - Chicago)
ZTSB:  Nashville
ZTSP:  New York, and to a lesser degree Hollywood


The job numbers which follow the ZTSC, ZTSP, ZTSB codes were allotted out of the offices in the Fisher Building in Detroit, and were often allocated in batches. Columbia Special Products Detroit office was first located in the Fisher Building during the mid '60's. Orders taken by the office would then be sent to Columbia's Chicago studio to have the master lacquer (acetate) cut, which would then be forwarded on to the plant in Terre Haute. Stereo 45 matrix numbers from NY/Hollywood always bore a ZTS prefix; Chicago used ZCSV prior to 1969, and ZTSV thereafter; Nashville's stereo matrix prefix was ZSSB.  EP releases bore the following prefix codes:  ZTEP = New York/Hollywood; ZTEC = Chicago; ZTEB = Nashville.  (E denoted an EP release.)  

In addition to the prefix code and job number, there would also be a number/letter combination at the end - the number indicates the tap/mix used, whilst the letter refers to the lacquer used. Only the letters A to L were used, excluding I:
 A 1st cutting; B 2nd; C 3rd; D 4th; E 5th;  F 6th;  G 7th;  H 8th;  J 9th;  K 10th;  L 11th; AA 12th; AB 13th; AC 14th; AD 15h etc - note that lacquers were made at the same time to then be sent out to pressing plants - therefore lacquer A does not necessairly reflect the "first press" - it is possible to have "1A" on one side of a disc and "1D" on the flipside. The example pictured ZTSC104309 1A illustrates that the recording was most likely pressed in Chicago, that the first recording/mix was used and that it was the pressed from the first lacquer.

From 1971 to near the end of that decade, Columbia also owned and operated a studio in San Francisco, however, no custom codes were used there.  Chicago, Nashville, New York and Hollywood were only venues of recording studios operated at one time or another by Columbia - in terms of their pressing, besides Pitman (opened 1960, ceased pressing vinyl records in 1986) and Terre Haute (opened 1953, closed 1982 then converted to CD manufacture) they had another plant in Santa Maria, California (opened 1963-64, closed 1981).  Prior to 1964, Columbia also operated an East Coast plant in Bridgeport, Connecticut, and another West Coast factory in Hollywood which was NOT where their studios were there.  A company called, Customatrix was a division of Columbia's pressing operations that handled the making of metal parts (i.e. mothers, stampers) for such pressings by Columbia. 

Mercury Label Family

For the entire listing of release dates and/or mastering completion dates, may I suggest you buy the book called simply, "The Mercury Labels" published by Greenwoord Press. It is a five book series with volume 3 concentrating on lists, by master number, for every Mercury/Smash/Philips plus subsidiaries like Limelight, Blue Rock and so on, from the years 1964 through to 1969. They usually have a"MR scrathced into the deadwax.

RCA-Victor Records

Every disc on the RCA label, it's subsidiaries, and indeed the myriad of independent labels which utilised it's mighty mastering and pressing facilities, feature a letters and numbers. During the mid-60's they had four recording hubs of New York, Chicago, Hollywood or Nashville. Their codes can be broken down  -e.g. 
634P-0987
634P:  is the account number of the client, or the info for the company / person who initialised the account (not a release date). 
0987:  is the master number referencing the tape used to make the master. 

The other part of the code that is included on independent labels pressed by RCA, as well as the label itself, can also be broken down. Once again, the second set of numbers refer to the master tape reference number, but the first part of the FOUR DIGIT CODE tells us the following -e.g. 
TK4M-0987:

THE YEAR: 
Noted by the first letter - In the example
TK4M-0987, the T denotes a 1966 year of mastering and not always the actual year of release, but it usually is accurate 95% of the time and is a useful rule of thumb. The RCA year codes are thus - 
L - 1960  |  M - 1961  |  N - 1962  |  P - 1963  |  R - 1964  |  S - 1965  |  T - 1966  |  U - 1967  |  W - 1968  |  X - 1969 
Z - 1970  |  A - 1971  |  B - 1972  |  C - 1973  |  D - 1974

One can then pin-point the disc further, as if the account number - in the example of TK4M:
If the "4", Is BEFORE the "K":  mastered between January and June of 1966.
If the "4" is AFTER the "K":       mastered between July and December, 1966. 

THE FORMAT: 
K
= 45rpm if there was an L = 7" 33 1/3 rpm; R = 12" 33 1/3 rpm; P = 10" 33 1/3 rpm 
(An EP actually retained the 'K' in the third position, while 'B' in the fourth position was mono and 'A' was stereo.)  

THE TYPE OF ACCOUNT: 
 4:  
Custom and re-recorded from client's furnished tapes -i.e. the client recorded at their own venues, then took the tapes to any of the RCA 
studios which then cut the lacquers. 
5:   Custom job where the lacquer was furnished to RCA -i.e. cut at a non-RCA studio.  

RECORDING TYPE: 
M: 
mono.
S:    stereo. 

In addition to the above, most independent label releases also have a letter stamped into the dead wax which indicates which plant was used: 
R:  Rockaway, New Jersey 1947-1976.
I:    Indianapolis, Indiana, (50 miles Northeast of Bloomington at 7900 Rockville Road) 1939-1987.
H:  Hollywood, California 1947-1976.

Finally, during 1966, their Chicago studios were apparently so busy that their last set of numbers put the number (3/4/5) in the first position and the year in the second (4TKM!).  And as to the period up to 1962, the second position was 7, 8 or 9 (indications same as 3, 4 or 5, respectively, post-1963), 'O' was their code for "Phonograph," and 'W' denoted a 7", 45 RPM release.  (i.e. L7OW, M9OW or NO8W).


Monarch Pressing Plant Disc Dating 

Monarch was one of the major manufacturing / mastering plants based in Los Angeles on the West Coast of the US. It's possible to date their work to the month and year of release via the
Delta number - see the grid below. 

Each disc has their 
MR within a circle machine-stamped into the deadwax, and then a Delta number , which consists of a scratched in triangle shape followed by a 5 digit number. It appears on both sides of a disc with an X added for the B.side. Note that the Delta/triangle system was not exclusive to Monarch, and other companies such as ALCO ( see below) also utilised it indicating that they produced the metal masters for pressing from. Record labels may use one company to produce the masters and another to actually press the discs - Monarch had the capability to manufacture discs. It is also worth noting that another metalwork company, AFM Engineering could also press records, but they used vinyl whereas Monarch produced styrene discs, which were injection moulded rather than 'pressed/stamped' out vinyl, hence a more logistically faster/more efficient manufacturing.

An awful lot of their presses utilised styrene rather than vinyl, which continued on into the 1970's - note there were plenty of Northern Soul second issues manufactured by Monarch, which tend to have numbers starting with 8, 9 or 10, instead of earlier original release, if indeed they were 60's recordings.
Please note the Monarch numbers stated below are guidelines and based on mid-month releases, so numbers either side may fall between months. These numbers were based mainly around the Dot label and put together by Warren Cook for the "Record Exchanger, vol.2. iss.4. in March 1972.

Kaybank - Minneapolis

Found hand-etched in the dead wax; almost always printed on the very bottom half of the label, this prolific plant located in Minneapolis, MN pressed many upper mid-west 45's, and a large amount of 45's recorded in the Carolinas. Starting in December, 1964, Kaybank began prefixing their numeric code with the number pertaining to the calendar year pressed (4=1964, 5=1965, etc.). Sight reading this number will yield the release year, but compare the remaining four digit # to approximate the month. Below is Mike Markesich's original grid which he has pieced together recently and I thank him for allowing me to share it with you...well done Mike, and keep up the good work!

Independent Record Plants
inc. mastering, stamping and metal part manufacturing


Allentown Record Co. Inc. - Pennsylvania
1947-1982 featured 
ARC stamped in the dead-wax. Mainly albums.

Audio Matrix, Inc. - Bronx, New York
People would send their lacquers aka acetates to them and they would prepare the metal parts necessary to manufacture records, icluding masters, mothers and stampers. Their work always had a machine stamped 
Audio Matrix in the deadwax more often than not almost unreadable as stampers wear leading to the depth of the actual stamp getting more shallow.

Allied Record Co. - Hollywood
1962 to 1996 (bought by WEA in 1979). Used injection moulding styrene and featured a hand-etched 
X followed by a four-digit number in the 1960's - discs from the early-to-mid 1970's used K

ALCO -  Los Angeles
OPerated between 1942-1987 and located on the north west corner of Santa Monica Blvd and El Centro in Hollywood, almost diagonally across from Gold Star, located almost on the south east corner of Santa Monica and Vine. Primarily a record pressing plant with 24 manual presses for vinyl. A delta sign in the dead wax does not always lead to Monarch, as other mastering/metalwork producers shared the delta system -i.e. ALCO did the metalwork for Doré, but AFM Engineering (vinyl), an associated company, did the pressing. Sometimes, as in the case of Monarch, a company did both. ALCO mastered discs have a machine stamped stylised 
A, L and C all within a circle. A delta number also does not necessarily mean that a record was pressed on the West Coast -  ALCO did their mastering from West Coast studio lacquers (e.g. Gold Star, Capitol, Western Recorders & Radio Recorders) and produced the metalwork for the pressing houses - these could be sent to both West Coast (AFM Engineering) and East Coast (Long Island Stamper Co. in Long Island, NY), who in turn produced stampers for pressing houses in the New York and Philadelphia areas. 

American Record Pressing Co. - Michigan
1952-1972 and based in Owosso in Michigan - closed due to a fire, their presses had the infamous 
ARP initials stamped in italics, and an AM label matrix for Atlantic label.

Artisan Sound Recorders - Pasadena, LA.
A mastering service started during the mid-60's - their machine stamp is a capital 
A with two circles eminating from the top - it sometimes appears as an oval with what appears to be two drumsticks sticking in it.

Audio Manufacturing Record Co. - Lakewood, NJ. 
Pressed records for their own children's labels, but also for London Records, Bell Records (later becoming Arista Records and Time Life). The plant opened in '68 and closed in '89. 

Bell Sound - New York 
A fairly large operation operating out of 237 W 54th Street, NYC, that stamped in 
Bell Sound in an italic script on many independent records.

Bestway Products - Mountainside, New Jersey
A pioneer in the making of styrene records, they pressed for such labels as Bell, Yew, Scepter, Dimension and Perception/Today.  Some of their labels were printed directly on the record itself (no paper label).  Identified either by a stamped 
B or Bestway in the deadwax, or later an S in a "spade shape".

Cook Labs - Stamford, Connecticut
Look for a 
CO on the label, followed by a three or four digit number.

Criteria - Miami, Florida
Criteria was probably Miami's busiest studio, and all kinds of music was recorded and mastered there, including garage, soul, funk, lots of Latin music and all kinds of easy listening and lounge sounds. Jack Davis was their chief engineer and did most of the mastering there through '69...finding a scratched in 
JD (with the two letters joing on a single upright line) in the dead wax indicates his work. During '69 the JD symbol was replaced with different initials -- usually CTW (Charles T. Wright) or ME (studio owner Mack Emmerman).  Fortunately the numerical code stayed consistent, so records mastered at Criteria can still be dated using the code.

Decca - Gloversville & Pinkneyville
The Gloversville factory opened in 1953, and Pinkneyville in 1958 - both changed to MCA Pressing Plant in 1966. Gloversville used an 
arrow or four-leaf clover design after the label matrix on the b.side.rage, whilst Pinkneyville a solid Triangle.

Houston Recorders - Houston, Texas
Recognisable from the 
LH prefix on the label.

Long Wear Stamper Company - New York City
An 
LW followed by a number found on the label, or if absent, always in the deadwax (etched)...still active today.

M.S.I. Co. - Philadelphia
This company is infamous for the
raised machine-stamp matrix with the backwards "M.S.I.COunder the label...it is the one found on Sandbag Records for the Epitome Of Sound's classic, 'You Don't Love Me'.

Midwest Record Pressing Inc. - Chicago, Illinois
MW followed by a three or four digit number sometimes on the label, always in etched in the deadwax.

Matrix Of Nashville - Nashville, Tennessee
Based at 457 Chestnut Street, next door to Southern Plasctics (later URP) at #453. this company made metal parts for the local pressing plants - their work bears the stamped in italic, 
Nashville Matrix wording, sometimes confused as saying "Nashville Mains", due to a worn out stamper.

Nashville Record Productions Inc. - Nashville, Tennessee
They were the largest of the Nashville based mastering services, with their client base including many famous labels - the client code number is etched into the deadwax: Motown (10), Hit (15), SSS (113), Monument (125), Paula (127), Dover (86), SO (5), PRP (161) SON (18) and small independant Detroit labels often had either 77 or 95. They used Matrix of Nashville stampers, so the "
Nashville Matrix" stamp is also to be found in the deadwax.

Plastic Products - Memphis, Tennessee
Atlantic singles pressed by the plant used a 
PL suffix after each matrix number on the record label to identify the origin thereof.  Note that they also pressed for Sun Records during its 1950's heyday. 

Precision - Nashville, Tennessee
Noted by a 
PRP prefix, the Precision Record Press out of Nashville also used Nashville Matrix for plating purposes. Their account number 161 and the Nashville Matrix logo are found in the deadwax, along with a 3, 4 or 5 digit master number, which is usually also on the record label. The last digit is either a "1" or "2" designated the main side of the disc. Note that the PRP code started during December 1967, replacing their previous code, "ZAFX", which has no connection to Columbia CBS affiliated pressings. 

QCA - Cincinnati, Ohio

Queen City Albums operated in Cincinnati, Ohio, and their mastering codes are fairly easy to date, - i.e. "QCA 91234" - the first digit 9 refers to the year 1969, the 12 is the month December. The last set of numbers does not refer to the day, but signifies the number of jobs completed to that point, in this case 112 mastering pressings were done in April of 1966, at that point in time. The codes change slightly for the 1970's, - i.e. "QCA 305322" reads as 1973 and the next two digits 05 signify the month of May. 

Rainbo Pressings - Santa Monica
An 
R code on the label and sometimes a R machine stamped into the dead wax. This company is still in operation.

Recordings Inc. - Baltimore
Noted by an 
RI followed by a four digit number either on the label or in the dead wax -i.e. RuJac label.

Rite Sound - Cincinnatti, Ohio
So many small labels used their services yet none of them seemed to ever have a hit! Recognisable from the either a machine stanped or hand-etched 
RITE in the deadwax, and often a dip in the vinyl/label.

Sheldon - Chicago, Illinois
Their name is often mistaken as Shelton due to the italic script they used. Records that were mastered / plated by
 Sheldon bear the stamp. If Sheldon pressed the record, then there will be a three or four digit matrix number that can appear on the label, but is always found in the dead wax (S 4355). 

Shelley Products Ltd - Huntingdon Station, N.Y.
They pressed for many East Coast major labels such as Liberty, Imperial and World Pacific, alongside cult independent ones, such as the Red Bird family and the infamous Shrine label. A raised machine stamped 
X  in the styrene pressings used, and often the actual record labels seem to come adrift from the discs due to poor quality adhesives used...this improved post-67. During 1969, the "X" was replaced with a backwards S within a circle. This company also owned the Golden Crest label.   

Sonic Recording Products - Long Island, N.Y.
1950 - changed its name to Goldisc Recording Products in 1975. Identified by 
SOL or SON hand-etched in the dead wax (mostly post-1970). 

The Sound Of Nashville - Nashville
Recognisable from the 
SoN prefix on the label.

Southern Plastics / United Record Pressing - Nashville, Tennessee
Dating back to 1949 and originally based at 512 Franklin Street, they relocated to #453 Chestnut Street, next door to Matrix of Nashville and changed their name to United Record Pressing Inc. during 1971...they are still in operation! Their 
SO codes began during the early 1960's and are sometimes noted on the label, but always etched in the dead wax, followed by a 3 or 4 digit number. Note in some cases the SO code does not appear in either location, and you'll then find a number "5" and a Nashville Matrix script code in the dead wax. 

Specialty Records Corp. - Olyphant, Pennsylvania
Started in 1946, pressed for Atlantic/Atco for many years, and whose pressings were identified by a machine stamped uppercase 
S with a small R inside the top half of the letter, and a small C inside the bottom half, which was backwards before 1972 and forwards thereafter.

Stereo Sound - Chicago, Illinois
This plant operated out of Chicago and was started by a former employee of the Chess label family group. A 
SS is always found as a prefix followed by a four digit number, i.e. SS 4622-01A, The 4622 is the master number which yields a date, and the 01A suffix refers to the side designation of the song. The SS refers to the fact that the song was recorded "in house" at their studio. A second code using the letter "M" refers to outside recordings brought in for mastering and pressing. Those codes read, -i.e. 7701-01M. The M replaces the A or B designation used in the SS code. Some discs may omit the M letter or the SS code (there was no consideration to the fact that somebody would want to know these intricacies 35 years later), thus the identifier to cite a Stereo Sound press is the suffix 01A, or 01B which always follows the master number in the dead wax. 

Superior Plastics Company - New Orleans
This was Dover Distribution's pressing plant based at 340 Brooklyn Avenue. The offices for the record company, studios, pressing plant, and distribution company were all at 748 Camp Street. Dover was the label distribution arm that  handled labels such as Manhattan, U-Doe, Busy-B, White Cliff, Hot Line, Apollo etc. The recording studio was known as, 'Cosimo', named after the New Orleans record kingpin owner, Cosimo Mattasa. Dover discs were often mastered and plated by Nashville Matrix, noted by the script stamp logo in the dead wax, and the number
86 followed by a four digit number, indicating a Dover based account. 

SJW - Wakefield Pressings - Phoenix, Arizona
Recognisable from the 
SJW prefix on the label and dateable mastering numbers.

Ter-Mar Mastering - Chicago, Illinois
Based at the Chess label studios and recognisable from the 
TM prefix on the label. 

H.V. Waddell Co. - Burbank, California
Featued a 
W stamped in the dead-wax and at the end of the label matrix for London records. Closed in the mid-80's.