I am wanting to create a header overlay for my website Cyankart.com, but the images I create do not seem to fit all browsers and devices. My theme doesnt support responsive design. Would it be possible to create a variable image using photoshop which would adjust accordingly to the browsers and devices or will I have to do this via code?
You'll need to do it with code. There is nothing in Photoshop that will resize an image on the fly after it is saved.