You can sell something you knit from a pattern you bought from a designer or got for free on a blog or website. But give courtesy by mentioning the name of the designer of the pattern when you post your finished projects, whether intending to sell or not. Most designers will be flattered that you recognized their talent instead of claiming all the fame and glory. You may not make little changes to a pattern and claim it as your own and give away to friends. The designer holds the intellectual property rights to the words written on it and should have rightful claims to profits if the pattern is passed from one person to another. Some designers post their patterns for free online for people to practice their knitting skills. Giving respect to their efforts, talents, and rights, you can drop a line to the owner to inform that you used the pattern to earn from your knitted project. It is also improper to use the photos or images of the designers’ finished items to sell your finished projects. The pictures you should show your clients are those you completed with your own hands.