If you are the creator of any kind of artwork, including a line drawing or other illustration, then you are the copyright owner of that work. It's important to remember the legal rights inherent in copyright, as well as the registration process for actually protecting your copyright in the eyes of the law.
Register your copyright online through eCO, the electronic copyright office. This procedure is faster than a mailed registration application; in addition, the fees are lower. Go to the U.S. Copyright Office and click on the button marked “Electronic Copyright Office.” The service is available 24 hours a day, and allows you to make a secure payment for registration and “deposit” the illustration by uploading it to the site. The Copyright Office will e-mail you an acknowledgment of the application.
Apply using a hardcopy form, if you are unable or unwilling to file for registration via the Copyright Office website. You may download copies of the necessary forms from the Copyright Office site; click on “Forms” and access Form VA and Form CON. You may either print out blank forms or complete the forms online, then print them out. Mail the completed forms to the Copyright Office with the current required fees and a copy of the illustration you wish to register. You may register two or more illustrations as long as they are deposited together, carry a single title as a collection, and have a single creator or group of creators as the registration applicants.
Receive a registration certificate from the Copyright Office. The effective date will be the day the office received all the needed elements of the application, including the application form, the filing fee, and the deposit of the illustration you wish to register. On this date, your illustration is legally protected from use or reproduction by anyone else without your permission.