You can do the same without using an image-editing program once you understand how to use Tumblr's HTML editor.

HTML is the language most used to build web pages. It provides a lot of flexibility in building interactive and dynamic web pages. For example, you can use an image as a clicking button for a ...

Ryan Boudreaux includes all the code snippets you'll need in this demo of how to create an image hover-preview effect using HTML, CSS, and JavaScript.