CSS Masks by WebKit

First CSS Gradients, and now WebKit introduces us CSS Maks. Masks allow you to overlay the content of a box with a pattern that can be used to knock out portions of that box in the final display. In other words, you can clip to complex shapes based off the alpha of an image. Here […]

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First CSS Gradients, and now WebKit introduces us CSS Maks. Masks allow you to overlay the content of a box with a pattern that can be used to knock out portions of that box in the final display. In other words, you can clip to complex shapes based off the alpha of an image.

Here is a snapshot of the Speed Racer movie trailer clipped to the Safari compass icon. This is in fact a mask applied to the <video> element.

We have introduced new properties to provide Web designers with a lot of control over these masks and how they are applied. The new properties are analogous to the background and border-image properties that already exist.

-webkit-mask (background)
-webkit-mask-attachment (background-attachment)
-webkit-mask-clip (background-clip)
-webkit-mask-origin (background-origin)
-webkit-mask-image (background-image)
-webkit-mask-repeat (background-repeat)
-webkit-mask-composite (background-composite)
-webkit-mask-box-image (border-image)

Use of a mask results in a stacking context being created (similar to how opacity and transforms work). The mask will therefore overlay the child and all of its descendants, and at a minimum will knock out everything outside the border box of the object.

About The Author

Deepak Gupta is a IT & Web Consultant. He is the founder and CEO of diTii.com & DIT Technologies, where he's engaged in providing Technology Consultancy, Design and Development of Desktop, Web and Mobile applications using various tools and softwares. Sign-up for the Email for daily updates. Google+ Profile.