Print Coloring Pages: A4 and Letter PDF Geometry Audit

ColoringPagesTools research · Version 2026-10-02-v1 · Updated October 2, 2026

The paper size and the picture size are different measurements. In our disclosed set of 24 locally reviewed dragon illustrations, the Letter PDFs have an artwork canvas about 3.20% wider than their A4 counterparts. Both preserve the source canvas proportions. This is a measurement of 48 actual PDF files, with downloadable samples; it is not a physical printer test.

Compare A4 and Letter · Inspect the results · Download the evidence

What to check before printing

Download the PDF, then select the paper actually loaded in the printer. Inspect the preview for the complete illustration and its margins. For an activity where physical dimensions matter, check the print application's scaling setting separately from the PDF's own size.

Adobe distinguishes keeping a page at its original scale from fitting it to the printer's printable area. These options can produce different physical output, even from the same file. See Adobe's PDF scaling instructions. The numbers below describe the downloaded PDF before the print application applies any further scale.

A4 versus Letter

The disclosed illustrations use portrait canvases with a 3:4 width-to-height ratio. The exporter places that canvas within the selected page using a fixed nominal 36-point margin. A4 is narrower; for this cohort its width limits the canvas. Letter gives it more horizontal room.

The width calculation is 540 ÷ 523.279872 = 1.0319525533. That is approximately a 3.20% increase in width. It is not a universal conversion ratio between A4 and Letter: a different illustration ratio, orientation, margin rule or print setting can change the result.

Citable finding: In the frozen ColoringPagesTools cohort of 24 portrait 3:4 illustrations, paired Letter PDFs place an artwork canvas approximately 3.20% wider than the A4 versions under the exporter's disclosed margin rule.

Results from the 48 PDFs

Citable finding: All 48 PDFs in this frozen local cohort are single-page files with the expected A4 or Letter page dimensions, no raster Image objects, no detected clipping operators, and minimum canvas margins of approximately 36 points.

These are canvas bounds, not the tight boundary of the dark ink. An illustration may leave empty space inside its canvas. The absence of a clipping operator also does not prove that every shape lies within the page or that a printer will retain every edge.

How the audit works

We selected every entry marked reviewed_local=true in the frozen September 26 dragon audit: 24 distinct asset IDs. This is a complete selection from that local review state, not a random sample of the whole library. Current publication of those assets is not asserted.

For each pair we checked the original manifest and PDF SHA-256, opened the real PDF, read its page dimensions, decoded its content streams and identified the canvas placement transform. We calculated the four canvas margins and aspect-ratio error, inspected indirect objects for raster images and counted clipping operators. Page-size checks used a 0.01-point tolerance; the reported margins retain their measured rounding differences. An independent calculation checked the public rows and all 48 archived file hashes.

Choosing a useful print setting

For an ordinary coloring activity, a complete, unclipped illustration is usually the immediate goal. Use the preview to confirm it. For a cutout or another size-sensitive activity, obtain the creator's physical dimension requirement and check the printed result with a ruler; this audit does not certify such a template.

If the picture looks small, distinguish empty space inside the illustration canvas from the PDF margins and any extra scaling performed by the print application. Enlarging the image can trade white space for clipped edges. Check one sheet before committing to a batch.

Downloads and reproduction

• All 48 frozen sample PDFs, ZIP
• Per-file results, CSV
• Dataset with input SHA-256, JSON
• Summary results, methodology, limitations and sources
• Independent recalculation script

Save the dataset, summary, sample ZIP and script together, then run python3 reproduce.py. The script recomputes the reported geometry summaries from the disclosed rows and checks every archived PDF hash. It does not independently parse PDF objects or test a printer; the object inspection is described in the methodology.

Scope, corrections and reuse

This is first-party research from ColoringPagesTools on its own frozen local artifacts. We did not test printers, paper stock, ink use, durability, developmental benefits or therapeutic effects. Vector storage does not prove recovery of detail from the original raster line art. Do not generalize these results to all current library pages.

To cite this work, name ColoringPagesTools, this page's title, version 2026-10-02-v1, the relevant section and the 24-illustration cohort. Preserve the distinction between file geometry and physical printing. Report a correction with the asset ID and measurement; updates should receive a dated change note rather than silently replace this dataset.

Ready for an activity? Browse coloring pages. For a new illustration from your own idea, open the text to coloring page generator; see plans and credits before choosing a paid option.