What is free, and what is not
The sample and the evidence are free. The book and the instrument are licensed.
A platform whose claim is that its figures close has to let people check the proof. So the evidence sits outside the paywall permanently: the source index, the measured residuals, the library of published figures, the colour records — and Part I of the book with the verse chapter, so the argument can be read before it is bought.
What a licence buys is the work itself: the complete book — the same text as the printed edition — and the studio, where figures are made: five parameters, every condition, every named figure, the animated construction, and exports from SVG to CAD to a carvable solid.
Reader
The sample and the evidence, free. Part I of the book, the annotated sources, the library of published figures with their residuals, and the colour evidence. The complete book and the instrument are licensed.
- The book’s opening — Part I and the verse chapter, free to read
- The full source index and what we measured against each claim
- The library of published figures, residuals shown on the page
- The colour evidence, source by source
- No downloads, no studio, and the book past its sample — those are licensed
Practitioner
The studio, unlocked — every parameter, condition and named figure — with print-ready files at any size your printer will take.
- The complete book — thirty-two chapters and the appendices, online
- The studio: five parameters, every condition, every named figure
- The step-by-step traditional construction, animated
- SVG, PDF with bleed and crop marks, and the certificate page
- Raster to 1200 dpi, sizes to one metre, no maker’s mark
- The construction table, for drawing by hand
- The kūrma drawing, in both projections
Workshop
For making things. CAD and every three-dimensional format, the stacking plates, and a licence to sell what you make.
- Everything in Practitioner
- DXF for laser, router and engraver
- STL, 3MF, glTF, OBJ, PLY and AMF
- The nine stacking plates, nested and labelled
- Commercial licence — sell what you make
- Sizes to five metres
Institution
For temples, museums, universities and manufacturers. Everything, plus the API and named support.
- Everything in Workshop
- API access for batch generation
- Unlimited size — architectural scale
- Named support, and help with a specific commission
- Citation and provenance records for catalogue use
Prices are not set. Every figure above marked placeholder is exactly that — the entitlement logic is complete and tested, the numbers are a commercial decision and nothing in the code depends on them.
Every format, and what it needs
| format | what it is for | included from |
|---|---|---|
| SVG | Vector, resolution-independent, with named layers. Opens in Illustrator, Inkscape, Figma and Affinity. Also the source for the raster exports. | Practitioner |
| Print-ready vector, with optional bleed, crop marks and a certificate page. | Practitioner | |
| DXF | For laser cutters, CNC routers, engravers and CAD. Geometry only, one DXF layer per element group. | Workshop |
| STL — text | The Meru as a closed mesh. Universally readable, but large and unitless; the slicer has to be told these are millimetres. | Workshop |
| STL — binary | The same solid at about a fifth the size. Prefer this unless something refuses to open it. | Workshop |
| 3MF | What modern slicers want — PrusaSlicer, Bambu, Orca, Cura. Carries its units, so it lands on the plate at the size you asked for. | Workshop |
| glTF / GLB | For the web and for game engines: three.js, Babylon, Godot, Unity, Blender. Flat-shaded, because the Meru is a stepped solid. | Workshop |
| OBJ | The Meru for Blender, Maya and anything that will not take the others. | Workshop |
| PLY | Indexed and compact, for MeshLab, CloudCompare and Open3D — if you mean to process the mesh rather than print it. | Workshop |
| AMF | The ISO alternative to STL. Carries units and colour. | Workshop |
| Stacking plates — SVG | The Meru as nine flat plates nested on one sheet, with the thickness of each printed beside it. Cut the black, engrave the grey, stack in order. | Workshop |
| Stacking plates — DXF | The same nine plates for a laser or router, one layer per plate, cut and score separated. | Workshop |
| JSON | Every coordinate, every intermediate, the residuals and the certificate. | Practitioner |
| CSV | The nine triangles as a table, in millimetres. | Practitioner |
| Construction table | The nine horizontal lines and half-widths, for drawing by hand. | Practitioner |
| Polylines | Raw polylines by layer, for writing your own exporter. | Practitioner |
| Kūrma SVG | The spherical form as vector line work, in your choice of projection. Free, because Part VI is the least-corroborated part of this work and its only picture should not sit behind a paywall. | Practitioner |
| Kūrma PDF | Print-ready vector of the spherical form, with the certificate page. | Practitioner |
| Kūrma DXF | The spherical form for CAD and cutting. Note that this is the projection, not the curved surface — a domed plate needs the drawing wrapped onto it. | Workshop |
| Kūrma plate STL | The domed plate itself — the figure incised into a spherical cap, watertight and printable. Not the flat drawing: cutting that out and bending it would put every line in the wrong place. | Workshop |
| Kūrma plate glTF | The same solid, for viewers and rendering. | Workshop |
| Kūrma plate 3MF | The same solid, with units carried in the file, for slicers that honour them. | Workshop |
| Kūrma data | Six parameters, derived arcs, both residuals, the cap proportions, and the minimum cap radius below which the figure does not exist. | Practitioner |
| PNG / WebP / JPEG | Raster, rendered in your browser from the SVG. Resolution is what the tier allows. | Reader |
What the limits actually do
Worth stating, because a paywall whose gaps only the seller understands is not an honest one. The Reader tier includes SVG, and SVG is vector. Anyone with it can rasterise at any resolution or scale to any size using tools they already have. The dpi and size ceilings bound what this application will do — which covers most people — and bound nothing at all for anyone who thinks about it.
Two things are genuinely enforced. The maker’s mark is written into the SVG itself and survives into anything rendered from it. And the format set holds, because the CAD and mesh files are generated on the server and simply never sent.
So the honest description of Reader is: the mark, and the four formats. Making the ceilings real would mean withholding SVG — and then nobody could inspect the geometry, which was the whole reason for putting the scholarship outside the paywall. That trade is a decision for whoever runs this, and it has not been made.
The state of this
No payment provider is connected and no accounts exist. The entitlement rules are written and tested — 4 tiers, every format mapped, every limit enforced server-side in the export route — but there is nothing yet to buy with, and the switcher below is a development tool rather than a purchase.
The gate is real in one respect worth stating: the tier is read on the server and never from the request body, so a client cannot obtain a format by asking for it. When a provider is wired in, the entitlement will come from its record in the database, and this cookie disappears.
Set the tier this browser claims, to exercise the export gate. It is a cookie: it proves nothing, grants nothing beyond this local build, and will be removed when a real provider is wired in.