I'm requesting an early TAG design review of exposing unprintable areas via CSS.

Most printers have a small region along each edge of the page sheet which is unprintable, due to the printer's paper handling mechanism. See https://drafts.csswg.org/css-page-3/#page-terms

The size of these unprintable areas are available to applications (such as browsers) in most OSes, but currently it's not web-exposed. This means that authors have no means of confidently setting page margins to prevent content from getting clipped. This becomes a more obvious shortcoming for @page margin boxes for e.g. custom headers and footers. See https://drafts.csswg.org/css-page-3/#margin-boxes

• Explainer: https://github.com/mstensho/unprintable-areas

• Security and Privacy self-review: https://github.com/mstensho/unprintable-areas?tab=readme-ov-file#are-there-any-privacy-security-and-accessibility-considerations

• GitHub repo: https://github.com/w3c/csswg-drafts

• Primary contacts:

  • Morten Stenshorne (@mstensho), Google, spec proposal and implementation
  • Tab Atkins-Bittner (@tabatkins), Google, editor of css-env

• Organization/project driving the design: Google

• Incubation and standards groups that have discussed the design: https://github.com/w3c/csswg-drafts/issues/11395

• Standards group(s) that you expect to discuss and/or adopt this work when it's ready: CSSWG

• Multi-stakeholder feedback:

  • Mozilla comments: https://github.com/mozilla/standards-positions/issues/NNN <!-- And/or other places they've given feedback -->
  • WebKit comments: https://github.com/WebKit/standards-positions/issues/NNN <!-- And/or other places they've given feedback -->

• I have reviewed the TAG's Web Platform Design Principles