Most Blue Note pressings made during the 1950s exhibit a deep groove on both sides of the label central area. After around 1960, new pressing dies which left no deep groove were introduced into the manufacturing process, and original first pressings thereafter have no deep groove on either side. The two types of groove are illustrated below (record sawn in half, not Photoshopped, honest!)
The opposite of the expected – no deep groove on a Fifties release, or a deep groove on one or both sides of a Sixties release, indicates a second or later re-pressing of an earlier release. Only a handful of titles during the changeover late 1960 early 1961 (mostly between BN 4059-68) are known exceptions with deep groove on one side and no deep groove on the other. In the five years that followed, coinciding more or less with the introduction of the NY (New York USA) label, the first pressing of around 180 titles by Blue Note all have no deep groove.
Despite all this, sellers shriek “DG!” and buyers foam at the mouth and frantically throw money at the merest mention of deep groove, as if it were a badge of authenticity. According to authorities, from 1961 onwards Plastylite used the newest machinery and the new non-DG dies for all new releases, and older equipment for repress jobs. Many earlier titles, pressed originally in relatively small numbers, were re-pressed between 1961-6 on New York labels with deep groove on one side or both. However, as always with Blue Note, there are anomalies. Consult Fred Cohen’s book on identifying first pressings for specific details on all releases by Blue Note Records.
The presence or absence of deep groove is helpful and in many cases definitive in establishing the authenticity of a pressing as a “first pressing”, or otherwise. It is not a guarantee of superior audiophile performance, which is impacted by many other factors. Second and subsequent pressings by Plastylite employed stampers derived from the same intermediate metalwork and original master lacquer cut by Rudy Van Gelder, and still sound distinctively “Blue Note” – bloody marvelous. The deep groove is, in reality, an inconsequential by-product of the manufacturing process – see the LJC Slackers Guide to making records below. Gain “Instant Expert Status” and immediate respect from less knowledeable collectors.
LJC ” Expert in Thirty Seconds” Slacker’s Guide to making records
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Step One – from music to stamper
Music cut by lathe onto a master lacquer, all that important information (catalogue number, master engineer signature, Plastylite ear) stamped or written here on the run-out area of the soft lacquer, mother/stamper positive/negative metal pressing images created, final stamper central area punched out, paper labels trimmed and center-punched ready for use.
Step Two – from stamper to finished record
Hot vinyl biscuit sandwiched by labels is mounted between side A and B stampers, the press applies 100 tons pressure to the biscuit at a temperature near 200 C for 30 seconds, pressing the grooves from the stamper image into the vinyl. As the press lifts away from the newly pressed record (bottom right) you see the indentation left behind in the central label area by the metal dies holding the stampers in the press. Deep Groove, or not Deep Groove, this is where it all happened.
Congratulations.You are now a fully certified 30-second Vinyl Expert, saving nearly four minutes on watching the whole Discovery Channel You Tube.
Origins of Deep Groove
The deep groove has its origins in the pressing 78 r.p.m. records. The deep groove circle is just slightly smaller than the label of a 78, located within the label edge. As the recording and distribution medium switched from the breakable shellac 78 first to the 10″” and then 12″ unbreakable microgroove 33/1/3 LP, with its larger label, the deep groove was incorporated into the design of the new labels. Deep groove remained a feature during this period until pressing plants commissioning new presses to keep up with the expanding demand for vinyl records, phasing out the old presses, and with them, the older deep groove dies.
(Thanks to Cristian for the info on 78 rpm)
Other record labels and the Deep Groove
Deep groove impression is found on many other record labels such as Riverside and Contemporary pressed around this time. There is not as much documented about how these fit into the chronology of other pressing plant processes as there is for Blue Note and the Plastylite vinyl pressing plant. Eight different types of pressing die grooves from late Fifties to early sixties, ranging from Plastylite-like on Contemporary, to deep pudding bowl on Verve
An example of more PPM – pressing plant mayhem – is this interesting “anomaly” on the Prestige label (photo courtesy of Albert of Ohio) of Coltrane’s 1958 recording Black Pearls, first released by Prestige in August 1964. Stereo copies of the original pressing exist with different label designs, one with deep groove, another with no deep groove.
Anyone with a more serious interest in the subject of pressing die indentations on record labels, I recommend to seek professional help.