How each printable page is generated

Paper dimensions

ISO A4 is 210 × 297 mm and A5 is 148 × 210 mm. US Letter is 215.9 × 279.4 mm and US Legal is 215.9 × 355.6 mm. Landscape swaps the width and height without changing either physical dimension.

Pattern geometry

Square and lined paper use repeated parallel lines. Dot paper places a mark at each grid intersection. Isometric paper combines horizontal and diagonal line families. Hex paper draws regular six-sided polygons with equal side lengths.

Output formats

SVG stores the vector page in millimeters. PDF converts millimeters to points using 72 points per inch and 25.4 millimeters per inch. PNG is rasterized in the browser at a target of 300 pixels per inch.

PDF points = millimeters × 72 ÷ 25.4

Validation and limits

Inputs are limited to usable ranges and the page must retain a positive grid area after margins. Automated tests cover paper dimensions, pattern commands, output headers, and invalid values. Printer scaling, non-printable hardware margins, toner spread, and paper movement remain outside the file generator’s control.

How to verify a print

1. Download PDF and choose actual size or 100% in the print dialog.
2. Disable fit-to-page or shrink-to-printable-area options.
3. Measure several intervals together with a reliable ruler.
4. If edges are clipped, increase the page margin rather than scaling.