When I finally complete a painting, I typically sign my name or intials in the lower right corner of the picture. I do this to show authorship, authenticity, and to preserve ownership of copyright.
I highly recommend that an artist takes the time to include a personal signature or mark somewhere on the front or back surface of the artwork to assist in claiming copyright. Any work of art that lacks a visible signature or mark often leaves a viewer in mystery about the identity of the artist who made it. Based upon personal experience, I have found that not everyone will turn the frame over to look at the reverse side of the artwork and that any photographs of such artwork, therefore, will not show the authorship.
The majority of modern artists today choose to place their signatures on the lower right corner. On occasion, though, I have seen artists sign on the vertical right margin, lower left corner, or middle of the bottom margin.
When a logo is preferred in place of a signature, it is advisable that the artist has the logo trademarked to protect the artist’s original claim on the logo. Even with a logo in use, I recommend that the artist shows a name of authorship on the reverse of the art for personal recognition and legal reasons.
Additionally, it is important that an artist remains consistent in signature style and placement as much as is practically reasonable and possible. Later purchasers may not be certain that a work of art is genuinely by the same creator if signatures vary dramatically in an artist’s collection, especially if the artist is no longer alive to validate the authenticity of the work.
Charity Goodwin, Artist