I have people ask from time to time what rules apply for copying another design, what needs to be changed, how much needs to be changed, and if you can get in legal trouble for using someone else’s design and changing part of it. I have always been told that if you change another design at least 20%, there won’t be a chance of getting into legal trouble. I have done some research on this issue, and it seems the lines are blurred. Some articles say you can get into trouble, some say you can’t, and that it’s more on an ethical issue. However, I’d say if you took Starbucks logo, and simply changed the name on it, there would be repercussions. I’ve personally never had an issue with design plagarism, so I can’t say from experience, but I have done some research on this, and found these pretty good articles.
For the most part, this one states there are no repercussions, and it’s an ethical issue, rather than a legal one. It’s worth reading.
This article says you can take legal action if you see that someone has copied your work, and lists step by step what to do. Great article.
Here are some examples of blatant copying/examples of what not to do to avoid trouble.
So, wrapping up the issue, in my opinion, try to do your own thing. Sure, draw some inspiration from beautiful creations around you, that’s the heart of design, but take that inspiration and create your own artwork. If you do want to take something and manipulate it, make sure it doesn’t resemble what you have taken it from so there can’t be a possibility of an issue coming up. Be safe. Ciao.