Problems with the CSS z-index property

The z-index property specifies the stack order of a creative element. An element with a higher stack order number appears in front of an element with a lower one.

Z-index problems that may occur include:

• shine-through issues
• an ad is expanding behind site content
• an ad is layering above the site's drop-down menus

These issues arise when a creative is assigned a higher or lower z-index than another element on the page.

Possible fixes

Publisher

If possible, reset the z-indexes of your site's content accordingly.  By default, Studio sets the z-index between 999999 - 1000000. If a site element must expand over an ad, ensure that its z-index is higher than that of the creative.  If a site element must appear under an ad expansion, set its z-index at 999998 or lower.

Agency

To make sure that a creative properly shows above site content, set its z-index higher than that of site content.

To make sure that a creative doesn't show above site content, set its z-index lower than that of site content.

The z-index shouldn't be set below 5000 if the ad is targeted to multiple sites. If a z-index must be less than 5000, you'll have to duplicate the ad or creative for the site with the problem only, so you don't affect other sites negatively.