Ampex (later known as Quantegy) 632 reel-to-reel audio tape - 600 feet on 5 inch reel
This was the standard 1.5 mil low-print-through version of "The industry standard for low-cost, non-backcoated analog open reel applications." The tape is brown-oxide, low-noise, high-output duplicating tape and offers a general all-around good performance. Designed to operate at 185 nW/m.
"Quantegy’s 600 series offers a low noise/high output tape with improved capabilities over standard output products. The lower noise and higher output provide an improved signal-to- noise ratio. An exceptionally smooth recording surface, the result of the Quantegy Ferrosheen™ process, enhances close head-to-tape contact and allows improved high frequency response. Special attention is given during manufacture to maintain uniformity within each batch and between batches to meet the consistency needs of demanding users. Extra care is given to slitting and winding to assure smooth handling at all winding speeds "