Erhum ... Otenth, Grace, and Vint ...

(now you've gone and done it: you've invoked the wrath of my day-job avatar!!)

As I have suggested emphatically and repeatedly above, this is a LEGAL issue and, as such, should not be an area where you are providing advice unless you are qualified to be doing so. Having said that ...

Do NOT use Wikipedia as the "final authority" for this topic (copyright). If you want good clear concise information on copyright, then I suggest (for the US, anyway ... and Peter will respond to you if you ask him nicely) going here and reading what Peter Hirtle has to say:

http://www.copyright.cornell.edu/public_domain/

'mkay? This is about as clear, and authoritative, a overview as you are going to get of US copyright. If you want information, ask a librarian or archivist. We ARE the Information Professionals, after all, and have been for over 5,000 years. And, of course, consult with legal counsel for legal advice.

Vint, I know you are being jocular about Bosch, but it isn't about Bosch ... it's about the Prado. The Prado OWNS that painting now and as such, they hold the copyright. And, as Otenth has sussed, they probably own the copyright on the unattributed photo that was taken to be used in a textbook or to document their question, especially since they have taken the precaution to copyright every page of their website. THAT photo was most likely done by a staff member (work for hire,no copyright to the photographer) or a photographer hired to do the job. Either scenario, they own the painting, and as such, OWN THE RIGHTS TO HOW THAT IMAGE OF THE PAINTING GETS USED.

IF, and it's a an assumption of trying to piece together the events that led to the image of Bosch's painting being in SL, the image cane from a textbook or postcard, there was almost certainly an agreement of use of the image to be published on that postcard or book. This agreement constitutes a license.

When you get a license like that, you are restricted to only using it for the purposes spelled out in the license. This isn't supposition on my part; it's hard-earned first-hand knowledge. I still have the photos to prove it and, in my day job, I deal with this issue regularly.

Here's what hasn't been addressed:

1. Who provided the Bosch image?
2. From what source was THIS version of the image taken?
3. Did the person who provided the source of the image HAVE PERMISSION to use that image in this manner (rights of reproduction in electronic or digital format are our main concern here)?
4. What restrictions of use are spelled out in the source of this image?

I ask because here's what the Prado has to say about their website, just to give you an idea of what this is all about:

http://www.museodelprado.es/en/pie/aviso-legal/

"Intellectual property

All the content of the web portal, texts, graphics, images, their design and the intellectual property rights that may correspond to this content as well as any brands, commercial names or any other logo or sign are the property of the Museo Nacional del Prado or of their legitimate owners, and all related user rights are reserved.

It is not permitted to reproduce partly or completely the contents of the website in any form or medium (mechanical, electronic, reprographic or any other type). Also forbidden is any type of promotion, public communication or distribution of these contents without the prior, written permission of the MNP or the legitimate owners of the content in question.

As set out in articles 8 and 32.1, second paragraph, of the Law of Intellectual Property, the reproduction, distribution and public communication of part or all of the content of this web portal for commercial ends is strictly forbidden, on any support and using any technical means, without the express permission of the Museo Nacional del Prado."

Do you see the nuanced layers of ownership there, in that first paragraph? And likewise, at the end of the second paragraph? "Or legitimate owners of the content in question" ... that's legalese for covering your arse. Likewise, the little hand grenade at the end of the last paragraph: "...without express permission ... ".

Goddess! Now I need some caffeine ...