IE8: Disable cleartype?

Juliano, body{ filter:none } is a better, cleaner solution. Using opacity causes problems in some situations.

To answer all the ClearType enthusiasts--I like ClearType too. I think it's a great advancement for LCD monitors. Problem is that when IE tries to use ClearType on some specific elements, it looks worse than if you had ClearType disabled. These include elements that are faded into view (using javascript) as well as imported @font-face fonts. If you like ClearType, then you're going to hate what IE does when it tries to use ClearType in these situations...your text looks chunky, fat and ugly.

In these cases, ClearType should be removed if possible to achieve the smooth fonts you guys want.

You can't. ClearType is a user setting on the browser. Any CSS which would disable it for certain elements is most likely a bug, not a feature (I've noticed it gets disabled for some dynamically generated or animated elements) and shouldn't be relied upon.

Whatever your preference in this regard is is probably not the user's one who sees your site. So why bother? Whoever doesn't like ClearType probably has it disabled already.

Note: The reason why it works with filters is that filters are not rendered by the browser but something else (DirectX probably, considering the "DX" in there. I'd still consider that a side-effect, and not a feature).

Note 2: Fixed as of IE 9, as expected. This really is a battle you can only lose, as many have told you before except you wouldn't listen.

From what I recall, Internet Explorer 7+ disables ClearType when a filter is set on an element

#target {
    -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(opacity=99)";
    filter:progid:DXImageTransform.Microsoft.Alpha(opacity=99);
}

_{Also, do consider that many users may find disabling ClearType to be annoying. Use sparingly!}