Thumbnails with rounded corner in html/css?

I would like to spruce up my gallery thumbnails a bit by giving them a frame with rounded corners.

Is it possible to overlay a second image on top of the thumbnail that acts as a frame?

IF I understand what you’re trying to achieve, I’d recommend creating your “frame” using a button with rounded edges, carving out its interior, and saving as a PNG-24, which supports full transparency. Theoretically you should then be able to place that over your existing thumbnails.

Yes, making the image shouldn’t be too hard, I just wasn’t sure how to layer one image atop another in that way.