Shelly, I am happy that you asked the question.
There is a very fine line here. As a quilt designer and pattern maker, here is my take on the whole thing..
There is a wealth of traditional blocks that are in the public domain.. Where these are concerned, you can use them however you wish...Make them out of the same fabrics...redraft them,,,
What you cant do is take someone elses work to draft the pattern, and reproduce the pattern and distribute it in any way. That is their work.. they created the directions.. this is a definate no no. The law says that any creative endevor is owned by the creator and protected by copyright law even if it isnt registered with the copyright office.
There are antique quilts that are unique. These are owned by someone.. It is not ok, in my opinion to copy them without the permission of the owner of that quilt.. You cant use the image of these quilts either...For instance, if you saw a picture of one of my quilts on the board, downloaded and reproduced it, without my permission, that would be a no no,, If you did it and never showed it, how would I know, so you would probably get away with it, but you should just ask first.. Most people are very forgiving when asked..
Now, If you see an original piece of work.. my quilt for example, you should either ask for permission to copy, ask for a pattern you can buy, or go on to something else. Most people dont have the skills to reproduce anyway. But many people who produce original art work do not want it to be copied, and it is protected...
Ok I have reread this and Im sure you are still confused....
But I will tell you that even the professions abuse other peoples patterns and work.. So I suggest you just be as considerate as you can and dont copy a real original..