Must the head-tefillin's four passages each be written on a separate parchment, while the arm-tefillin's four passages are written on a single parchment?

Synopsis

All authorities agree this is a fundamental requirement: head-tefillin has four separate parchments (one per passage), while arm-tefillin has all four passages on one parchment.

Early Acharonim
Lenient
Strict
Lesser cited
Major authority

Discussion

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