This subject is boring, yes, but necessary.
Patterns and books are copyrighted.
That means, under United States Federal Law, that you may make the item so designed within specific limits.
You buy a pattern or book of patterns to make the item which is the subject of the pattern, right?
But how far does that go?
Can you make them to sell?
Can you make many whether or not you sell them?
Can you give copies of the pattern(s) to others?
Can you make copies for yourself?
It's the Pattern Author's right to limit how many you can make.
If the Pattern Author (PA) doesn't specify on the pattern, you still don't have unlimited use. The Copyright Law protects the PA's intellectual property, which is what any work of authorship is. Even if the Copyright symbol © or a copyright claim isn't printed on the pattern, the PA still has the rights provided under the law.
Since the PA has invested knowledge, time and effort in the design of the pattern(s), it's only fair, even if you don't consider the law, that he or she is compensated for the use of the pattern(s). That's why you pay for the printed (or digitized) pattern.
But it doesn't stop there.
Some think that if they own the pattern (they really don't) they can copy it and give the copies to others. The truth is, the purchaser of a pattern is paying for a limited license. They don't get to OWN the pattern at all. It remains the Intellectual Property of the Author. So, you can make the item designed by the PA, but you do not have the right to sell it for a profit without the specific permission of the PA. What you own, therefore is the printed copy of the pattern(s) and not the design itself.
Here's the bottom line: Unless you have permission from the PA DO NOT Copy, Scan or Reproduce by any means or distribute by any means any published pattern or book! The law gives the PA rights to enforce these rules and some PAs do so with vigor.
And that's that!