Is this true? Paper (and I assume papyrus) expands and contracts with varying humidity even below the saturation point, and this motion embrittles and cracks it, no? So consistent humidity is key, and "consistently dry" is much more achievable than "consistently at an arbitrary other point."
Only because humidity is measured relative to the vapor pressure at a given temperature. It only matters for preservation when humidity reaches 100%.
Is this true? Paper (and I assume papyrus) expands and contracts with varying humidity even below the saturation point, and this motion embrittles and cracks it, no? So consistent humidity is key, and "consistently dry" is much more achievable than "consistently at an arbitrary other point."