- From: Christoph Päper via GitHub <sysbot+gh@w3.org>
- Date: Thu, 18 Jun 2020 13:34:15 +0000
- To: public-css-archive@w3.org
<aside> Recommended minimum legible font sizes in DIN 1450 are indeed based upon angles, as are ergonomic character heights in ISO 9241 Parts 30*x*. DIN 1450 also prefers ex-height over em-height to specify font sizes (which CSS needs `font-size-adjust` for), but it also offers a mapping table to millimeters and pica points. [](https://imgur.com/a/ImRHQNn "a Zeichenabstand f Serifenabstand g Stärke der Grundstriche h Stärke der Haarstriche l Grundlinie m Mittellänge o Oberlänge s Schriftgröße u Unterlänge v Versalhöhe w Wortabstand z Zeilenabstand") | | | _Signalisationstext_ (public signs) | _Konsultationstext_ (notes, captions, legends) | _Lesetext_ (main, body, paragraph) | _Schautext_ (headings, titles) | | - | ---- | ---- | ---- | ---- | ---- | | *m* | x-height, `1ex` | 9′– | 10′– | 13′– | 20′– | | *g* | stroke width | 0.17ex–0.20ex | 0.13ex–0.20ex | 0.10ex–0.20ex | — | | *h* | hairline width | 0.12ex–0.19ex | 0.06ex–0.19ex | 0.04ex–0.19ex | — | | *n* | font width | 0.45ex–0.55ex | 0.48ex–0.58ex | 0.40ex–0.60ex | — | | *a* | character spacing, `1en` | 0.45ex–0.55ex | 0.40ex–0.60ex | 0.35ex–0.65ex | — | | *f* | serif spacing | — | 0.10ex | 0.05ex | — | | Reading distance | _Signalisationstext_ (public signs) | _Konsultationstext_ (notes, captions, legends) | _Lesetext_ (main, body, paragraph) | _Schautext_ (headings, titles) | | ---- | ---- | ---- | ---- | ---- | | 0.4 m | | 2.75mm = 7pt | 3.5mm = 9pt | — | | 1 m | 5.25mm = 15pt | 6.25mm = 17.5pt | 8mm = 23pt | — | | 2 m | 10.5mm = 30pt | 12mm = 35pt | 16mm = 45pt | — | | 4 m | 21mm = 60pt | 25mm = 70pt | 32mm = 90pt | — | | 10 m | 53mm = 150pt | — | — | — | | 40 m | 212mm = 600pt | — | — | — | | 100 m | 530mm = 1500pt | — | — | — | ISO 9241 assumes a preferred viewing distance for desktop monitors of 600 mm, varying from 450 mm to 750 mm with a minimum viewing distance for adults of 300 mm. Usual LCG character heights are then 20′ to 22′ with a minimum of 16′ and a maximum of about 30′, whereas typical CJK character heights are 25′ to 35′ with a minimum of 20′. On an ideal, paper-like display, the LCG minimum could be as low as 10′ to 12′. ISO 24509, on the other hand, estimates minimum legible font sizes by age (for visual acuity), distance, luminance level, contrast, font type (serif/sans-serif) and writing system (alphabetic/syllabic/logographic), which results in vast tables which have been implemented in an online tool by [AIST](http://scdb.db.aist.go.jp/db/vision/charsize.html?lng=en) that is referenced in the standard. -- GitHub Notification of comment by Crissov Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/4430#issuecomment-646020480 using your GitHub account
Received on Thursday, 18 June 2020 13:34:16 UTC