I was recently asked to create some fullscreen video ads for Yahoo’s login page. The constraints were: dimensions of 1440×1024 but less than 500k file size, must loop seamlessly and no HTML5 blend-mode effects or plugins allowed – otherwise an overlay of the steam blended onto a canvas layer would have yielded an even smaller file size. Unfortunately, at the time of writing, Microsoft’s Edge browser did not fully support blend-modes – hurry up Microsoft! I managed to create a few videos, such as the one below, all within these constraints, using After Effects and the amazing WEBM format: