Very old question to put things in prespective let me post a quote about another area first:
"12 Nov 2009 - Yesterday there appeared an interview with a Microsoft group manager who claimed that Microsoft copied the “Mac look and feel in terms of graphics†in Windows 7. This was later denied by Microsoft’s communications manager."
Everybody remmembers Apple Macintosh and the first Microsft Windows versions surely.
Just took this example to show my point and my questions are this:
a) You see a lure and there is something in the design that you thing would improve it, you make your own version.
b) You get inspiration from lures you've seen and fishing before, put your own ideas and reach a new design, but the roots of the design are similar.
Is this ethical ?
I'm not asking if it's patented or legal that is a total different matter.
An intresting reading about the legal aspect of what Mikey is refering (mould production from original copy) in SA is the Schultz v Butt 1986 court ruling about the Buttcat design:
http://www.saflii.org/za/cases/ZASCA/1986/47.html
The legal implications of shaun2 question is simple:
"Anyone may ordinary make anything produced by another which is in the public domain: One may freely and exactly copy it without his leave and without payment of compensation."
I think the Berkley Nitro jigheads are also legalcopys of public domain lures, you can not pick up a public domain property and "make it your own" intelectual property, but you can copy it and in this case sell the final product.
P.S. - By the way this is a "lure copy proof of concept machine"
[flash=425,344]http://www.youtube.com/v/8oSMf_1nLqE&hl=en&fs=1[/flash]