Can I sell reproductions and copies of famous artists, or use known artworks/characters/brand logos in my own artworks?

Can I copy or use other people artworks in my own artworks?
No, you can not use or copy other people artworks, unless you have a written autorisation from the copyrights owners, or if the artworks are in the public domain.

Can I copy or use artworks in the public domain?
Yes, it is perfectly legal to produce and sell reproductions of famous paintings as long as they are in the public domain, and the artwork is clearly presented as a "reproduction".

When does an artwork falls into the public domain ?
In most countries, an artworks will be in the public domain 70 years after the death of the artist, with some additional requirements: each year of war count 2 years and thus extends the duration of the copyright. To be safe, you should only reproduce artworks from artists dead more than 100 years ago.

How can I reproduce artworks by famous living artists or artists dead less than 70 years ago?
No, you can not sell reproductions of famous artists, or artists dead less than 70 years ago, unless you have a proper autorisation from the artists, or the organisation managing his estate.

How to obtain the autorisation to reproduce artworks by famous artists?
All famous artists work with lawyers and organisations responsible for managing their rights. They will negociate the copyrights for the artist, and provide licences for any type of use you can think of. You shall look for the people managing the famous artist's copyright and contact them directly to request an autorisation.

Can I create famous painting reproductions, but not for sale?
It doesn't change anything: if the works are in the public domain, that's not a problem. If the works are not in the public domain, you must obtain permission.

Can I use famous artworks/characters/brand logos in my own artworks?
No, you can not use an artwork, or a known character (like a Disney characters, Marvel super heros) or a brand logo (Dior, Louis Vuitton etc...), unless you have a written autorisation from the original copyrights owner.

Why do some artists include known characters or brand logos in their artworks?
Some brands may have a tolerance for street artists using their logos or copyrighted designs, because they believe it makes their brand look "fresh" and good for social media. Nevertheless, any use of a known character from a cartoon, a movie, or a brand logo is forbidden, unless you have a written autorisation from the copyright owner, or the artwork is in the public domain. 

Artists using known characters or brand logos face the risk of legal consequences.