Both refer to Type II, where Chromium uses chromium dioxide (CrO2) as the magnetic material (real chrome tape), and “chromium type” uses materials other than chromium, such as cobalt-added iron oxide, as the magnetic material, which are used in the same way as chrome tape, such as equalizer and bias settings. “Chrome position” and “high position” refer to tapes that are used with the same bias and equalizer settings as chrome tape.
The meaning of “high position”: Chrome tape requires a higher (deeper, stronger) bias value setting than the normal type, so decks compatible with chrome tape are equipped with a special switch that allows setting the bias value higher (high level). It seems that tapes with such settings came to be called “high position tapes” because of the meaning of the position of the switch to be set.

CrO2 was first prepared by Friedrich Wöhler by decomposition of chromyl chloride. Acicular chromium dioxide was first
synthesized in 1956 by Norman L. Cox, a chemist at E.I. DuPont.
The magnetic crystal that forms is a long, slender glass-like rod-perfect as a magnetic pigment for recording tape. When
commercialized in the late 1960s as recording medium, DuPont assigned it the tradename of Magtrieve.
Unlike the spongy looking ferric oxides used in common tape, the chromium dioxide crystals were perfectly formed and could be evenly and densely dispersed in a magnetic coating; and that led to unparalleled low noise in audio tapes. Chrome tapes did, however, require a new generation of audiocassette recorders equipped with a higher bias current capability (roughly 50% greater) than that used by iron oxide to properly magnetize the tape particles.
Also introduced was a new equalization (70 µs) that traded some of the extended high-frequency response for lower noise resulting
in a 5–6 dB improvement in signal-to-noise ratio over ferric-oxide audio tapes.
DuPont licensed the product to Sony in Japan and BASF in Germany in the early 1970s for regional production and distribution.
Chromdioxid cassettes have the following advantages compared with low noise ferric oxide cassettes:
- A substantially improved high frequency response. The response is 6 to 10 dB higher at 10 KHz and 8 to 12 dB higher at 15 KHz.
- The undistorted output at low frequencies is 1 to 3 dB better.
- Print-through is 4 to 8 dB less and the stability of high frequency signals is insured.
- The particles of chromium dioxide are as small as the smallest low-noise ferric oxide particles, but considerably more needle
shaped.
- The particles are single crystals rather than being made of many crystals as is the case in ferric oxide. Also they are free from defects common to all ferric oxides. such as porosity and the formation of branches.