if you focus on the instructions and illustrations, you'll see why two authors can legitimately protect their patterns for what seems to be the same item.
the value is not necessarily in the bags themselves. it's in the quality of instruction and usefulness to those who buy them.
copyright protections are there to ensure others do not infringe upon the rights of the creators to realize benefit (usually money) from their unique efforts. they can't deny reasonable use. but, if somebody buys one copy of a pattern and then makes and sells several hundred or several thousand bags made using those instructions, the manufacturer is interfering with the creator's right to realize the income from selling the patterns.
clear as mud? :lol: