# PrintPlan — True-scale tiled print

> Print a measured outline across A4 or Letter sheets with alignment marks. Prepare SVG geometry at a measured physical size, inspect the assembly grid and export tiled PDFs with alignment marks and a 100 mm calibration square.

Part of usefulweb.app (https://usefulweb.app/). Part of [Paperwell](https://paperwell.usefulweb.app/) (ownerApp: paperwell). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://paperwellprintplan.usefulweb.app/ (interactive tool at https://paperwellprintplan.usefulweb.app/tool)
- JSON API: POST https://paperwellprintplan.usefulweb.app/api/v1/calculate with a JSON object of inputs (schema: https://paperwellprintplan.usefulweb.app/api/v1/tool)
- OpenAPI: https://paperwellprintplan.usefulweb.app/openapi.json
- MCP (Streamable HTTP): https://paperwellprintplan.usefulweb.app/mcp - tool `paperwell_printplan`

## Inputs
- width (number): Target width (mm)
- height (number): Target height (mm)
- source (textarea): SVG geometry (optional)
- paper (select): Paper
- orientation (select): Orientation
- aspect (select): Scale artwork
- overlap (number): Overlap (mm)
- margin (number): Printer margin (mm)
- title (text): Project title

## Method
- Reuses the Threadsmith vector path, flattening and tiled-PDF engines. Bézier curves, elliptical arcs, rounded rectangles and affine group transforms are supported; curves are flattened at 0.15 mm tolerance.
- The browser can trace a selected PDF page or PNG/JPEG image locally into bounded black-and-white contours, with threshold, inversion and sampling controls. This is contour extraction, not full-color reproduction. Direct SVG input rejects external references, scripts, text, clipping, masks and filters. Unsupported content is rejected rather than silently omitted. The target width and height define the printable canvas.
- Auto orientation selects the smaller sheet count. Print at 100%, check printer margins and measure the 100 mm calibration square before using a template.