Recently, whilst working on a client’s website I had to incorporate image overlays into their portfolio page. I had seen Mosaic mentioned before on various websites and blogs, but I had never used it. I was disappointed at the lack of documentation, but nevertheless it proved to be a nice, light (~2kb minified) jQuery plugin that did exactly what it said on the tin. I thought I would document how to get going with a quick mouse-over animated overlay which will hopefully save someone some time.