how to copywrite a pattern?

Technically, you probably already have. Copyright laws go into effect the second something is set into a 'permanent media' which not only includes paper, but also hard drives these days.

Of course, writing something down may not be entirely enough. It is sometimes a good idea to be able to prove WHEN you wrote something down...

The best low-budget means I've heard of to do this is to put a copy in a well-sealed envelope and mail it to yourself. The envelope will have a postmark from a federal post office which is good enough as evidence in any court of law. Then, if you are ever called to court to defend yourself, you can open the letter in court and use the court records of the date on the letter for any future cases.

Hope that helps!

You would have to be a bit more specific. What kind of pattern? Are you talking about an art design or graphic? Are you talking about a pattern for sewing or weaving? What kind of pattern are you talking about? Also you may be having trouble finding information because you are looking for a "copywrite" when it is in fact a "Copyright" that you should be looking for.