Agfa, BASF, and IG Farben Audio Open Reel Tapes














Copyright © 2006 by Friedrich K. Engel. Reproduction in any form prohibited without the permission of Friedrich K. Engel.











See abbreviations and notes at bottom.

















Manufacturer and Product Name Est. Prod. Start Est. Prod. End Appli­
cation		 Oxide Base Base Thickn. Oxide Thickn. Total Matt Back* Coer­
civity		 Coer­
civity		 Reten­
tivity		 Reten­
tivity		 Rema- nent
Sat. Flux		 Remarks
Material µm µm Thickn. Oe kA/m Gauss mT nWb/m



µm




Agfa PER 1961 1963 BRC acic PE 33 17 52 red 240 19,2
96 1630 -.-
Agfa PER 368 1984 1990 BRC acic PE 20 10 33 3 / white 355 28,4 1150 111 1110 -.-
Agfa PER 525 1963 1967 BRC acic PE 30 12 50 red 300 24 1000 100 1200 -.-
Agfa PER 525 stereo 1967 1981 BRC acic PE 30 13 50 red 300
1000 100 1300 -.-
Agfa PER 528 1981 1990 BRC acic PE 30 15 48 3 / white 355 28,4 1150 115 1725 -.-
Agfa PER 555 1963
BRC acic PE 30 18 56 white 300 24 1000 100 1800 -.-
Abbreviations and Explanations:














AC Cellulose acetate base













acic Oxide is g-Fe2O3, acicular













BRC Broadcast Tape













BRCLP Broadcast Tape, long play













CDMT Cassette Duplication Master Tape













CrO2 Oxide is CrO2













cub Oxide is g-Fe2O3 , cubic













DMT Digital Master Tape













DOM Domestic Tape













GEN General Purpose Tape













IGF I.G. Farbenindustrie Aktiengesellschaft (1925 – 1948)













PE Polyester base













REF Reference Tape (Bezugsbandleerteil)













PVC PVC base













STM Studio Master Type













Thicknesses given in µm (25.4 µm = 1 mil; 0.039 mil = 1 µm).














* Matt Back: number gives the matt back thickness in µm, followed by color.














































** Originally (2006-07-15) incorrectly shown as "PVC"; corrected 2007-12-13 per F. E.














+ Originally (2006-07-15) incorrectly shown as “PVC”; corrected 2009-06-24 per F. E.














++ Originally (2006-07-15) incorrectly shown as “cub”; corrected 2009-06-24 per F. E.






























Sources: Various data sheets by Agfa and BASF. Early tape data are selected from Müller, Rudolf, “On Improvements of Magnetic Tape Shown by Measurements on Early and Newer Tapes”, Journal of the Audio Engineering Society, 1988 October, p. 802 – 820; and Krones, Friedrich,” Die Theorie des Magnetspeichers”, in Winckel, Fritz (ed.), Technik der Magnetspeicher, Springer Berlin / Göttingen / Heidelberg 1960
Reference tapes are unrecorded magnetic tapes with specified characteristics, not to be confused with calibration tapes, magnetic tapes on which signals have been recorded, mostly used to calibrate reproducing amplifiers. See IEC 60094-5, Clauses 2.4 and 2.5.