Check out this post (http://forums.tumult.com/t/about-jquery-eraser-js/3400/6) as a way to achieve the scratch-off effect natively in Hype (i.e. without jQuery or external libraries).
Check out this post (http://forums.tumult.com/t/about-jquery-eraser-js/3400/6) as a way to achieve the scratch-off effect natively in Hype (i.e. without jQuery or external libraries).