@ajillustrates said in Inktober Book Plagerism Accusations:
would artworks for sale using the Inktober name or branding be in violation if they were produced before the filing or registration date?
The way it was explained to me, it can extend back so to speak. If the item were still being sold/used when the trademark is obtained the trademark owner can enforce their trademark. However, don't forget that more than one person can own a trademark on the same word/name under different classifications so that is another set of circumstances to deal with.