- From: Todd Fahrner <fahrner@pobox.com>
- Date: Sun, 7 Sep 1997 19:20:52 -0700
- To: Jordan Reiter <jreiter@mail.slc.edu>, www-style@w3.org
At 20:18 -0500 7.9.97, Jordan Reiter wrote: > I have a real problem when using font sizes with stylesheets. My >essential > problem is this: the incredible discrepancy in sizes between Macs and PCs, > IE and Netscape. IF I specify specific font-sizes, then I have a problem > with legibility between the Mac/Windows platforms. Mwah-ha-ha-ha-hah! <g> The problem is not so much in specifying sizes, but in specifying them in point (pt) units. As you have observed, "8-point" type is dangerously variable across platforms for screen display. The pixel unit (px) is more consistent, but those readers with sub-par eyesight, or whose displays have a relatively high pixel density (resolution/display size) will curse you for binding type size to pixels this way. It's a failing proposition anyway, because Nav 4 and IE 4 don't always rasterize even pixel-spec'd type identically! (Navigator gets it wrong on Windows, right on Mac.) The CSS1 Recommendation introduces the concept of a "virtual pixel", defined not as the smallest dot any display can produce, but as the degree of visual angle formed at arm's length by such a dot on a display whose physical resolution is 90 ppi. Browsers ("user agents") are supposed to scale pixels as necessary if the actual pixel density is "significantly" different, without saying more. Already Navigator has departed from this recommendation by scaling pixels for print assuming a display of 120 ppi. Your choices are, IMO: a. The Standards-Will-Save-Us Stance: Wait for near-universal deployment of CSS implementations so complete as to permit size specification/DOM queries of ALL elements (text, images, objects, form elements, frames, windows) in relative units like ems and percentages, where 1 em is the user's preferred (point?) size which s/he specifies in hir personal stylesheet on body. b. The OS's-Will-Save-Us Stance: Wait for near-universal deployment of operating systems whose displays are true WYSIWYG (72 points = 2.54 cm) regardless of pixel density, though perhaps adjusted for reading distance, visual impairment, etc. Part of user settings, like network password. c. The Pixel-Designer Stance: Write off those whose displays or eyesight are very different from yours. Make GIFs of all size-critical text. Make decisions about performance issues after you've got everything in your cache. d. The Web-Purist Stance: Don't specify sizes on anything. Don't attempt to correlate image or object sizes to text sizes. Pretend that users, "user agents" or the programmers of said agents, will make the necessary adjustments to render your documents readable, if not attractive (as if the two were unrelated). e. The Pragmatist/Mercenary Stance. Use browser/platform detect scripts to serve separate stylesheets to all the CSS implementations/platforms you know something about. For the rest, serve unstyled markup and resign yourself to stance d). Or if you're working for hire, mix in just enough of stance c) as required to please the client. See http://www.verso.com/agitprop/css/ . > If I specify a > font-size of 8pt on the PC, it looks fine on the PC but unreadable on the > Mac. However, if I use words instead (ie, x-small, small, medium, etc.), > then the size differences between Netscape and Internet Explorer come to > the surface. Have you "zeroed out" the browsers, setting the default size/face the same before concluding that they produce different results? Note that across platforms, the "12-point" factory setting is a cause of much trouble here. > Can anyone figure out a way, short of Javascript (UGH!) to define font > sizes so that they are readable on both Mac and PC platforms and on > Netscape and IE? If you don't like Javascript, there's Jscript, ECMAscript, or VBScript - the syntax for a simple detect and write-line is the same, I believe, so you needn't declare your religion. Or you can go server-side and use PERL or what have you. If there's another way, I'd truly love to hear it! __________________ Todd Fahrner mailto:fahrner@pobox.com http://www.verso.com/
Received on Sunday, 7 September 1997 23:20:31 UTC