A different reader changes the sentence
When a class wrote for its own school paper, it wrote for people who already knew the players. A mention of the yard, the broken gate, the teacher everyone called by a nickname — none of it needed explaining. The readers walked past these things daily.
The moment a printed sheet went into an envelope for a school two hundred miles away, all of that shared ground disappeared. The reader on the other end knew nothing: not the village, not the season, not what the harvest had been like or why the river was talked about with worry. The prose had to carry its own context, or the reader was simply lost.
Wall space caps the run. A line that holds sixty sheets is a print run of sixty.
This was not a small shift. It was, in effect, a lesson in what writing actually does.
A text set for local readers can lean on the world outside the page. Names, places and events float in a shared atmosphere that the prose barely needs to touch. Take that atmosphere away and the sentence must do everything itself. The correspondent school — the one that would receive the paper, read it, and eventually reply in print — became a useful fiction during drafting: a reader who is curious but knows nothing. Writing toward that reader forced the class to ask what the text actually said, rather than what the writer assumed it said.
The practical consequences showed up in small, concrete decisions. A proper noun needed a phrase beside it. A reference to the weather needed a month. Local speech had to be either glossed or replaced with something a stranger could hear without tripping. None of this required formal instruction; the exchange itself was the instruction. When a reply arrived noting confusion — we did not understand why this mattered to you — the lesson was already contained in the question.
The composing stick enforced a related discipline. Type is slow to set and expensive to correct; a text that was vague or elliptical when printed stayed vague and elliptical. There was no revising after the forme was locked. The obligation to be clear had to be met on paper, before a single piece of type was touched, which is one reason editing before setting became so tightly bound to correspondence work. Clarity was not a virtue the teacher imposed; it was a structural consequence of printing for a reader who would never ask you what you meant.
Writing for strangers turns out to be an old definition of writing.