Broad edge and pointed nibs: line weight on cotton paper

Measuring split geometry without magnification myths

A pointed steel nib records pressure through two halves that draw closer until they kiss the fibre. A broad edge measures angle instead of pressure; rotation around the axis yields ribbon widths tied to the grind behind the shoulder. On cotton paper pressed cold, the distinction matters because compressible fibres respond slowly compared with starch-coated wood pulp sheets tested beside them.

Rough grain versus polished grain

Canadian rag pads marketed for drawing often arrive with enough texture that a hairline appears darker along both shoulders of the stroke. When that happens, swap to the smoother side or rotate ninety degrees and redraw the line after resting the sheet — fibre bundles occasionally lie directionally. Referenced preservation framing practices from Library and Archives Canada remind studios that repeated abrasion removes gelatin size over decades; treat timed comparisons as single-session evidence instead of permanent benchmarks.

Link to fibre swelling tests

Follow the fibre swelling note on tooth and sizing before stacking inks across batches.

Regional calendars

Formal copperplate sessions vary by venue humidity; see the Ontario meetup index for typed schedules copied from public postings.

Bench checklist carried through Ontario winters

• Condition steel under warm water only long enough to loosen grease; drying cloth stays lint-free cotton.
• A brass flange twists slightly after seasons of vibration — inspect weekly before inserting fresh chrome finish.
• Ruling pen residue flakes onto rag sheets unless wiped toward the ceiling plane away from the grain.

For statutory wording around reproduction rights when photographing manuscripts for comparisons, keep federal summaries attached rather than paraphrasing filings; begin from Government of Canada intellectual property pages.