Playing with copy of Default Dark.css. I managed to add a white border around the thumbnails reminiscent of old photos. I'm now trying to find the style that controls this for the full size image.

I've never managed to accomplish this. I'm trying to make the image on the Image Page have a border akin to the old-fashioned photos that were developed with the white border. Tried
.image
border: 5px solid #FFF;

and #image
border: 5px solid #FFF;

both without success

Please see third post (by sbillard) here: http://www.zenphoto.org/support/topic.php?id=2599&replies=16

If you are talking about hte image on image.php that is not the full size image but the sized image...

Sorry, I did misuse the terminology. I mean the Image Page sized image. Keep forgetting you count three views (thumb, sized, full). Will write out 200 times as it will become problem when slideshow is used which I assume is the "full size" image :)

The ajax slideshow option uses the sized images (because some full size photos people use would break the whole screen...:-) and the flash option using Flowplayer the full size images (the players scales them), but it is possible to set a custom size value for the slideshow images on the theme slideshow.php page (see our functions guide about that).

Okay, will keep playing. I've decided that except for the opening page of the Gallery, I'm going to stick with only Default Theme and customize the CSS within. May keep things easier for now. I can do a "compare" to see what CSS you apply to new elements, quite easily.

Solved.

img {
border: 10px ridge #72587F; /* indigo around sized Image */

And this was solved while my computer monitor moved around the room (got vertigo).