I'm going slightly crazy here.

Searching for a source of good, calm, modestly-chic digital backdrops that are almost but not quite virtual sets.

They do exist. I can picture them - I found some about three years ago, but cannot (CANNOT) find them or anything like them after many trawling sessions. Think Le Corbusier interiors in a Mediterranean setting. Think the white room in Voodoo Lounge London.

Googling brings up too much '1980s Americana' - Dark blue or gritty grey sets with too much bodywork, steel and marble. Pale, muted colours, unobtrusive textures, geometric details, needs to be a background. Don't want people humming the sets! :)

Any recommendations before I have to commission my own?

google image search, select extra large images
corbusier - Google Image Search (http://images.google.com/images?q=corbusier&gbv=2&hl=en&safe=active&imgsz=huge)

google image search

Thanks Giroud, but what I was trying to locate was a company who do rendered backdrops, rather than using actual photos of architecture, where there may be issues of copyright for both the photographer and objects in the background. Even the architecture can be subject to copyright and permissions.

sorry I misread your post. I was going to suggest Digital Juice. Not sure that is what you want. (Jumpbacks) in fact pretty sure it is not.

You might try www.elitevideo.com, they have virtual sets.

I'm not sure if this is what you are looking for, but we used www.Virtualsets.com (http://www.virtualsets.com) for a project last spring. It was for a blue screen project that was for a luxury home timeshare/rental company. They (luxury home arch environments) looked VERY realistic.

As I recall, they weren't cheap, but they were very good. After checking a moment ago, I didn't see anything like what they did for us on their site, though. The stuff on their site looks like mostly broadcast sets, not architecture stuff they did for us.

-RD