CSS Line-Height Guide - css

I remember reading a style guide explaining what the proper line-height should be for each element. I can't find it on google.
I would appreciate it if anyone could link me to such a guide, or perhaps explain it in an answer.
Thanks!
Edit: SORRY, please let me clarify. I'm not asking about how to use CSS to set line-heights, but what the recommended line-heights are for various elements. eg headers, paragraph text, etc.
Thanks!

Maybe these references are more like what you're looking for. I haven't found a definitive rule, but at least here are some things to consider.
This one suggests that it depends on your choice of font-family:
http://www.webteacher.ws/2009/09/30/improve-readability-with-line-height/
This one suggests that it depends on the width of the lines:
http://kingdesk.com/articles/optimal-line-height/
This reference essentially agrees with both of those:
http://www.wpdesigner.com/2007/06/21/web-typography-line-spacing/
The main rules seem to be (1) wider lines of text require greater line-heights, and (2) greater line-height is required based on font if the height of lower-case letters is a high percentage of the height of upper-case letters.
The best approach is probably just to eyeball it, and try to avoid impenetrable walls of text.

The info here is pretty basic, but useful.
To summarize:
The default line-height:normal gives line-height:1.2, 120% of the font size. If you're going to change it, it's still usually best to use a number with no units, e.g., lineheight:1.5 (150% the font size), because then the line-height for an element will be computed from that element's font size, even if the line height was inherited from an element with different font size.
If you instead say line-height:10em, it's computed from the font on the element where the line-height was specified . . . that may be wrong if this line-height is inherited by an element with a different font size.
Likewise a specific number of pixels such as line-height:10px could certainly be wrong if it's inherited by elements with different font size.

It's usually 120% (of the font size).

W3 schools recommends (here) a line height of 1.6, though I've seen that between 1.2 and 1.45 is good as well

Normal line-height value is normal. You can edit that with numbers like 1.6 2 etc

Related

How to properly change font height in Font Forge?

When line-height in CSS is set to 1, my font vertically centered to lower letters.
When select letter
But I need center it to capitalized letters
Here is how it made in Roboto font
How to proper make it with Font Forge? I tried Element -> Transfomations and it works, but is it right way?
I have not experimented with how metrics change the appearance of selection highlighting within browsers -- and it's not entirely clear from your question what you're trying to achieve. But here's my advice for setting up metrics, which should be a good place to begin understanding your precise issue: http://benwhitmore.altervista.org/line-spacing-getting-right/
This may be possible by messing with the values in Element > Font Info > OS/2 > Metrics - by default I think Is Offset is checked, but if you uncheck that, you can manually set each of the ascent/descent values. Each of the settings has hover text that explains what they do, but short of understanding those (I'm not entirely sure I do), experimenting might be the easiest way to figure things out.
I had spent all morning looking for a tutorial for this. Here is a YT video that might help. I've figured that it's the ratio between the ascent and descent values that matters. In my case, the descent was 800 while the ascent was 2533 which was causing my font to be shifted more towards the top. When I reduced the descent to 600 and increased the ascent to 2733 (keeping the total same) with the instruction shared in the video, the font became much more centered visually.

CSS letter-spacing and proportional fonts

So I know that my question is pretty technical, but basically I would like to know specifically how the following CSS affects the display of text in <p> tags.
p {
letter-spacing:2px;
font-family:"Georgia";
}
I know that Georgia is a proportional font, that the designer has spent time crafting the spaces between letters to make the font more readable and visually pleasing.
But my question is how does the letter-spacing property affect this proportionality? Does this code add two pixels onto the spacing already defined by the type designer, or does it reset that spacing to two pixels?
This property is additive to what the font would normally use. So, 1px will increase it by a pixel. Sitepoint calls it "extra" space (with negative values allowed).
The W3C docs say the same thing:
"This value indicates inter-character space in addition to the default space between characters. Values may be negative..."
It is in addition to any default spacing.
See: https://developer.mozilla.org/en-US/docs/CSS/letter-spacing
From my experiment on Firefox on OSX, using a kerned font (Arial) as opposed to Georgia which does not appear to have kerning on my machine, I can testify that the spacing is in addition to existing spacing, and kerning, and can be either additive, or subtractive.
It is also worth mentioning that different browsers and operating systems replace fonts, and handle them slightly differently to each other, making it impossible to predict 100% how any font will be rendered.

Best unit for font-sizes in CSS

What are the advantages & disadvantages of each? em, px, % and pt ?
My current choice are percentages, the only reason is because I can globally change the font-size of all elements, just by modifying the font size on the root element (body)
I would recommend EM — simply because I use Baseline CSS for my basic set up of forms, layout and most importantly type.
Can't recommend it enough : http://baselinecss.com/
My original design training said em's where possible.
I believe a main reason was that different browsers and devices have different resolutions, which is once again becoming a big issue.
I think it's frequently better to use em's and %'s as they are an abstraction layer particularly when compared to pixels. Both are similar in some respects as "100%" = "1em".
Another problem with the pixel unit is that it does not scale upward for visually-impaired readers.
Today, for mobile, pad, etc. consideration it's often better to have specific stylesheets / rules for each one.
Also, for print concerns, em works well.
I have seen em unit called a standard for font sizes on the web, but the percent unit often gives a more consistent and accessible display. When user settings are changed, percent text scales well preserving readability, accessibility, and visual design.
Here is a link to one of my favorite articles on proper sizing of text with css from AListApart:
http://www.alistapart.com/articles/howtosizetextincss
Semantically, em is preferred, but I've always found it problematic because it impacts each child element inclusively. If your design nests 4 or 5 divs and each is at .75 em, by the time you get to the last child div your text is almost unreadable.
My preference is pt because it works with various operating systems (allowing the system itself to decide what a pt is) rather than using px which can really put a pinch on the readability of a site depending on resolution. Em is considered the "standard" for css, but it has just as many problems as the others, but it does have the advantage of cascading globally.
I always use ems. Using % is kind of the same, but they mean something else when using them in a padding or margin statement (padding:1em 0; is not the same as padding:100% 0;). So just use ems I you mean relative to the current font size, and avoid any confusion.
Added benefit or using ems is you could e.g. use a media query and body{font-size: 120%} to give mobile users a slightly bigger fontsize.
Nice question !
Me i'm using pixel because I like it when everything is fixed.
But checkout this article :
http://kyleschaeffer.com/best-practices/css-font-size-em-vs-px-vs-pt-vs/
could help you make a choice.
I think all this is very personal. Or it depend of what you are doing I suppose

How to use and manage relative font values as easy as we use px

what are cons to use relative values em and % for fonts, What is rounding problem? and how to avoid/solve rounding problem. Is there any calculator?
How to use relative values as easy as we use px
There are not a lot of cons using em or %.
Sometimes i had trouble to make fonts look exactly the same size in IE and the normal browsers. But most of the time i have to do a IE CSS anyway so its not really a problem.
When you define fonts in PX, the fonts are not antialiased on some computers running windows. If you use EM or % they are and you have a very precise control of the font size. (1.249em for example).
Unlike #scunliffe i would always use EM as font-size. Even when you have fixed design withs. Sometimes its not possible to do a pixelperfect design with PX fonts, because fonts rendered by Photoshop looks different then in the browser.
I have made a test tool to show the differences:
http://bluesys.ch/csstest/
and here you can find a tool to convert your PX values in to EM:
http://pxtoem.com/
I may be preaching to the choir here, but I find the Firefox "Web Developer" addon is a real help when I'm dealing with font sizing.
https://addons.mozilla.org/en-US/firefox/addon/60/
Use 'Information' > 'Display element information' to view the exact pixel size for your (relatively sized) element. Tweaking the CSS (to within 1 decimal point) until the amount returned is a round number minimises the chances of your text being different sizes in different browsers / operating systems.
Oh, and from my current project:
Standard (appearing as 12px) font set on site wrapper is 75% (body is 100%) , then use:
14px: 116.7%
16px: 133.3%
18px: 150%
18px: 166.7%
There are loads of reasons to not use fixed text sizes (accessibility being the big one), and once you've spent a while getting your CSS sorted you'll never look back.
Here's a nice little trick for you.
In the your CSS, set the font-size on the BODY of the document to 62.5%.
Now, whenever you want to set a font-size, you use EM values. 1.1em would be equivelant to 11px and 1.2em to 12px and so on.
That's how I work anyhow.
Good luck.
Michael.
I don't believe there are (m)any cons. Using px limits your ability to scale text in IE6 but otherwise using % or em should allow you to scale nicely.
The only con I can think of is that if you want your text to be exactly 12pt, or 13px then using % or em isn't what you want. However If you are trying to create a fixed width design where everything is measured out to the pixel I would advise against it. The Web is a free-flowing canvas... each user has a different sized window, personal font/zoom size choice and Operating System differences. Your content should look good on any screen by adapting to the real-estate you are provided with.
em vs px is like a holy war. Everyone has their own ideas on what's best. Using px is perfectly fine, the only real problem is that text will not resize in IE6.
One other issue is how much you will change your mind about the general font size. If you do everything in absolute values (px, pt), then decide the font size across the site is too small, then you might have to change a lot of values to make everything bigger. Conversely, if you do everything in relative values (em, %) then you want to change the size of one thing only, it will affect all its child elements.
In the end, the best choice is to simply be consistent.

Font size in CSS - % or em? [duplicate]

This question already has answers here:
What is the difference between px, em and ex?
(4 answers)
Closed 1 year ago.
When setting the size of fonts in CSS, should I be using a percent value (%) or em? Can you explain the advantage?
There's a really good article on web typography on A List Apart.
Their conclusion:
Sizing text and line-height in ems,
with a percentage specified on the
body (and an optional caveat for
Safari 2), was shown to provide
accurate, resizable text across all
browsers in common use today. This is
a technique you can put in your kit
bag and use as a best practice for
sizing text in CSS that satisfies both
designers and readers.
Both adjust the font-size relative to what it was. 1.5em is the same as 150%. The only advantage seems to be readability, choose whichever you are most comfortable with.
From http://archivist.incutio.com/viewlist/css-discuss/1408
%: Some browsers doesn't handle
percent for font-size but interprets
150% as 150px. (Some NN4 versions,
for instance.) IE also has problems
with percent on nested elements. It
seems IE uses percent relative to
viewport instead of relative to
parent element. Yet another problem
(though correct according to the W3C
specs), in Moz/Ns6, you can't use
percent relative to elements with no
specified height/width.
em: Sometimes browsers use the wrong
reference size, but of the relative
units it's the one with least
problems. You might find it
interpreted as px sometimes though.
pt: Differs greatly between
resolutions, and should not be used
for display. It's quite safe for
print use though.
px: The only reliable absolute unit on
screen. It might be wrongly
interpreted in print though, as one
point usually consist of several
pixels, and thus everything becomes
ridiculously small.
The real difference comes apparent when you use it not for font-sizes. Setting a padding of 1em is not the same as 100%. em is always relative to the font-size. But % might be relative to font-size, width, height and probably some other things I don't know about.
Given that (nearly?) all browsers now resize the page as a whole, rather than just the text, previous issues with px vs. % vs. ems in terms of accessible font resizing are rather moot.
So, the answer is that it probably doesn't matter. Use whatever works for you.
% is nice because it allows for relative resizing.
px is nice because it's fairly easy to manage expectations when using it.
em can be useful when also used for layout elements as it can allow for proportional sizing related to the text size.
As Galwegian mentions, px is the most reliable for web typography, as everything else you do on the page is mostly laid out in reference to a computer monitor. The problem with absolute sizes is that some browsers (IE) won't scale pixel-value elements on a web-page, so when you try to zoom in/out, everything adjusts except for those elements.
I do not know whether IE8 handles this properly, but all other browser vendors handle pixels just fine and it is still a minority case where a user needs to enlarge/diminish text (this text box on SO perhaps being the exception). If you want to get really dirty, you could always add a javascript function for making your text size larger and offer a "small"/"larger" button to the user.
Regarding the difference between the css units % and em.
As far as I understand (at least theoretically/conceptually, but possibly not how these two units might be implemented in browsers) these two units are equivalent, i.e. if you multiply your em value with 100 and then replace em with % it should be the same thing ?
If there actually is some real difference between em and % then can someone explain it (or provide a link to an explanation) ?
(I wanted to add this comment of mine where it would belong, i.e. indented just below the answer by "Liam, answered Sep 25 '08 at 11:21" since I also want to know why his answer was downvoted, but I could not figure out how to put my comment there and therefore had to write this "thread global" reply)
Yahoo User Interface library (http://developer.yahoo.com/yui/) has a nice set of base css classes used to "reset" the browser specific settings so that the basis for displaying the site is same for all (supported) browsers.
With YUI one is supposed to use percentages.

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