[undyboy91]

I recently bought the video from lynda.com for CSS Design and the instructor said that ems are the way to go. I personally really don't feel comfortable with ems knowing that a change in the font size would drastically change the outcome of my intended layout. Which unit do you guys prefer?

[wirehopper]

ems are good because you can scale them to the size of the other text.

[jfulton]

It really depends on what kind of layout you want. I do try to stay away from all px though. But you sometimes you need to use them, especially if your layout has lots of images/background images. Sometimes you need the precision, and sometimes you don't want your containers to expand with the text. It's really a matter of taste and the situation...

[Alan+61415484049]

Go with percents until you've drilled down to pixel level with your layout.
Then Go LARGE with this little css gem:-

Code:

/* highest element of the world: */
div#ems18939 { 
font-size: 100cm; 
height: 18939em; 
line-height: 1.0
}

This creats a HUGE div, impossible to scroll...

Gecko-based browsers like Firefox show an interesting behavior when a DIV is styled any higher than precisely 18,939 EM'S by “shrinking” or “collapsing” the container. Internet Explorer doesn’t accept internal references behind the real action, and it’s unclear if the container height really is 18.939 kilometers - about 11.769 miles.

http://worlds-highest-website.com/#hades

[pkcidstudio]

There are two types of length units: relative and absolute. Relative length units specify a length relative to another length property. Style sheets that use relative units will more easily scale from one medium to another (e.g., from a computer display to a laser printer). - W3C Relative units are:

• em: the 'font-size' of the relevant font
• ex: the 'x-height' of the relevant font
• px: pixels, relative to the viewing device

The .em unit can be troublesome, though theoretically it is ideal. Read the following from the W3C specs and note the potential pitfalls: The 'em' unit is equal to the computed value of the 'font-size' property of the element on which it is used. The exception is when 'em' occurs in the value of the 'font-size' property itself, in which case it refers to the font size of the parent element. It may be used for vertical or horizontal measurement. (This unit is also sometimes called the quad-width in typographic texts.)

[hen3rz]

I always work in pixels, its much easier to align images and backgrounds against them. Its also good cause you know exactly how it will look. Working with percentages means you cant be certain how it will appear in different sized browser windows.

[Vicious]

It's true that pixels are easier to align, or even measure in general. But for text, I think, it's better to use em's. My boss has a bad vision, so every time I demonstrate him something, he wants to put the text size bigger. If your text has a fixed pixel-height, he can't do that.

That's why I always end up with putting the text in em's, and avoiding fixed height elements (divs). Once max-height & max-width are fully supported in IE, you can make sure your layout still looks good, while using em's.