Handbook · 10 · Weeks 3–4 · Srishti Manipal Interim 2026

The pen plotter

Pen plotter production guide. One A2 plotter for the whole studio, so every slot counts. This is how to arrive with a file that plots first time.

seed plotter · depth 5

Machine: One A2 plotter
Sheet: 420 × 594 mm
Slots: 2 a day, Days 11–18
Each student: One test, one final
Files: SVG, strokes only

The machine

A pen plotter moves a real pen over paper, following paths in an SVG file. It draws lines, not pixels: no fills, no gradients, no transparency.

Sheet

A2

420 × 594 mm. Keep at least 15 mm margin on every side for clamping and tape.

Line

Strokes only

Every mark is a path the pen follows. Tone comes from density, hatching or repeated passes.

Colour

One pen per layer

Each colour is a separate layer, and the plot pauses for a pen change.

The plotter arrives in Week 2 and is demonstrated on Day 11. How long a full A2 plot takes is still being measured; until then, plan for a final plot of no more than two to three hours. To confirm on Day 11

Booking

Two slots a day, morning and afternoon, on Days 11–18: sixteen in all. That covers one test and one final for six to eight plotter students.

Book through the shared queue from Day 10, after you choose your pathway at Critique 2.
Arrive with a checked file. If the file isn't ready at the start of your slot, the next person in the queue takes it.
Stay with the plotter. Watch the first five minutes closely, and don't leave it unattended for long.
Have a fallback. If a final plot fails late in the week, the archival printer can take your work. Prepare a raster version too.

Preparing the SVG

Most failed plots fail in the file. Optimise paths before the slot, not during it.

Export from your system in millimetres.
The document should be 420 × 594 mm (or your chosen smaller size), with the drawing inside the margins.
Remove fills.
Convert every shape to a stroke. Anything filled will either be ignored or drawn as an outline.
Merge, sort and simplify paths.
The free tool vpype does this in one line. Ask Codex to install it with you if it isn't there.
vpype read outputs/production/final.svg \ linemerge --tolerance 0.1mm linesort reloop linesimplify \ write --page-size a2 --center outputs/production/final-plot.svg
Look at it before you trust it.
Open the optimised file next to the original. Check that no lines have disappeared and nothing moved outside the margins.
vpype read outputs/production/final-plot.svg show
Separate colours into layers.
One layer per pen, in the order they'll be drawn: usually lightest first.

Prompt 16 in the prompt library asks Codex to do this preparation with you and report the path count and drawing length.

Pens and paper

Pens

Choose for the line

Fineliners (0.1–0.8 mm): even, archival lines.
Gel pens: bolder, can skip on fast moves.
Brush pens: line weight changes with speed and pressure.
Always test a new pen on your paper first.

Paper

Choose for the ink

Smooth, heavy paper (200–300 gsm) stays flat and keeps lines crisp.
Textured or absorbent paper softens lines and can bleed.
Dense overlapping lines can soak and tear thin paper.
Keep a sheet of the same paper for tests.

Pen and paper are part of the identity's position, not a finishing detail. Say why you chose them in your spec sheet.

The test plot

Day 13. Plot a small section, about 10 × 10 cm, of the densest part of your drawing, on your final paper with your final pens.

Time it. Multiply up to estimate the full plot. If it's longer than a slot, simplify.
Check the ink. Does dense hatching bleed, pool or tear the paper?
Check the line. Does the pen skip, drag or blot at the start of lines?
Photograph it for your test log in tests/, with a note on what you'll change.

Spec sheet

Day 11, due by 3:30. Save as outputs/production/SPEC.md.

SPEC.md · plotter

# Production spec · pen plot

Final size: 420 × 594 mm (A2) / [other]
Margins: [mm]
Paper: [name, weight, colour] · why: [the identity's reason]
Pens and layers: [layer 1: pen, colour] [layer 2: ...]
Seed and parameters: [seed, params file]
Path count / drawing length (from vpype or Codex): [ ]
Estimated plot time: [from the test section]
Test plot: Day [ ] · notes: [ ]
Fallback: [archival print of the same seed at [size]]

When it goes wrong

Problem	Likely cause and fix
Lines are doubled or drawn twice	Duplicate paths in the SVG. Run `linemerge` and check for overlapping shapes in your code.
The pen draws between shapes	Pen height too low, or travel moves not lifting. Check the pen-up position before restarting.
The plot is taking far too long	Paths aren't sorted, or there are too many tiny segments. Run `linesort` and `linesimplify`.
Ink pools or the paper cockles	Too many lines in one place. Reduce density, change pen, or use heavier paper.
Part of the drawing is missing	Fills that weren't converted to strokes, or shapes outside the page. Check the SVG before the slot.