If you know the artist, you should make an artist entry and add an artist tag to all their posts.
To make a new artist tag, do the following:
Add an artist:artist_name tag to one of their posts.
Click the ? next to the artist tag in the tag list to go to the artist entry.
Under aliases, put the artist's Japanese name.
Under URLs, put:
links to the artist's website/blog/pixiv account/etc.
a direct link to an image hosted on their website/pixiv account.
Adding an image URL is necessary for the Find Artist function to work when their images are hosted on a different domain than the rest of their site (as is the case with pixiv accounts and sometimes blogs).
