Nowadays there is not a well supported way to create piecerced layers, there is no way to create a DIV element with an hole inside, maybe a visual hole but not a real hole through which interacting with underlaying elements. We could use the HTML5 canvas element, we can use static png image files but we will encounter problems with old browser and it will be always impossible to mantain interactivity with the elements under the pierced layers and we will probably face rendering errors and screen sizes incompatibilities. With Holesjs you will have an easy to implement method to highlight elements in your pages without worrying about browsers compatybility while allowing your visitors to intercat with those nicely highlighted elements.