Carbon fiber hybrid RF build notes.
Carbon fiber earns its own RF story: the woven face is conductive graphite, so it interferes with radio much like metal does — a carbon card is not an easy alternative to steel, it is its own engineered hybrid. The stack places the antenna in an RF-transparent layer behind the weave, trading some of the metal mass for lower weight and more antenna freedom. Tap performance is still proven per build, on the target phones and readers, before any batch.