Established as “Gramofonové Závody a.s.” (“Gramophone Record Factory”) in 1951, GZ is a leading manufacturer of records, cassettes and optical discs. This Czech based company is probably the largest record manufacturer in the world today and has expanded its record manufacturing activities to include investments in Canada, France and the USA. Operated under this name between 17 January 2000 and 31 December 2013.

Succession of names :
Gramofonové Závody since 1951.
Renamed to GZ Media (1 January 2014).

Vinyl matrix schemes ca. 1999–2003 - engraved in runouts:
AX #####/Z
“A” = verbatim, no particular meaning
“X” = format
“Z” = galvanoplasty

Vinyl matrix schemes ca. 2003–2013 - engraved in runouts:
#####X~/Z or #####X~~/Z
“X” = format
“~” = side number
“Z” = galvanoplasty

Main vinyl formats:
E = stereo, 12", 33⅓ RPM
F = stereo, 10", 33⅓ RPM
H = stereo, 7", 45 RPM
M = stereo, 12", 45 RPM
N = stereo, 10", 45 RPM
O = stereo, 7", 33⅓ RPM - "O" can sometimes be mistaken with a "0" (zero)
X = stereo, 78 RPM (very rare)

CD matrix scheme:
GZ XY#### (GZ prefix is sometimes omitted)
“X” = year of matrix manufacturing:
K=1999, L=2000, M=2001, N=2002, O=2003, P=2004, R=2005, S=2006, T=2007, U=2008, V=2009, W=2010, X=2011, Y=2012, Z=2013
"Y" = month of matrix manufacturing:
1 to 9=January to September, A=October, B=November, C=December

Glass mastering codes:
IFPI LD01 until 2001 and then IFPI LD02. When featured on the disc use Glass Mastered At role with the XY#### as LCCN.
Mould SID code: 5J**
** = numbers

“Q” was never used in the matrix schemes.
CD matrix will be stored for 2 years, i.e. any represses in that time window will bear the same number.
If the original CD matrix was damaged, a new one will be created with a new number.

How-to:
• When another company is etched into the runouts alongside the GZ Digital Media matrix number, please add a Manufactured By credit for that company in addition to the Pressed By credit for GZ Digital Media.
• For these releases with “www.gzvinyl.com” in runout area the “www.gzvinyl.com” entity can be used.
• All releases manufactured (and released) before 1999 (CD: year code “A” to “J”) should be listed under Gramofonové Závody.
• Use this entity to list releases manufactured from 1999 to 2013. Releases manufactured (and released) in 1998 or earlier should be listed under Gramofonové Závody. All releases manufactured in 2014 or later (CD: year code “A” etc. again) should be listed under GZ Media; do not confuse the actual release date with the year of manufacture though. 115067E vinyl matrix number is known to had been made still in 2013: for this reason, 2014 releases that carry a matrix number lower than 115067E should be listed under GZ Digital Media too.

LCCN how-to:
Vinyl matrix schemes ca. 1999–2003: Only the basic “AX ##### string should be entered with Pressed By role, without the galvanoplasty suffix. For example: AE 50022.
Vinyl matrix schemes ca. 2003–2013: Enter the numbers up to and including the first letter. For example: 75077M, 110557E, with Pressed By role. If at the same time “www.gzvinyl.com” string is found on run-out grooves use the role Manufactured By for it.

CD: only the “XY####” string should be entered, without the “GZ” prefix.
Glass mastering code: IFPI LD01 or LD02 - When featured on the disc use Glass Mastered At role with the XY#### in LCCN.
Mould SID code: IFPI 5J** - When featured on the disc use Pressed By role in LCCN.
"Glass Mastered At & Pressed By" - If both SIDs are present on the CD, both roles can be entered in the LCCN.