I had an idea that I thought did not exist but turns out it does exist and in fact I found many items for sale online (the material is different but the final purpose is the same). In that case I will not be going after a patent, but can I still go ahead and try to sell my item? How do I know if someone will sue me for selling the item? Thank you
This is a challenge everyone deals with. At the very least, you should perform a patent search. This takes some experience and some businesses farm this out to a patent law firm. If you want to take a crack at this, you can use Google Patents or even better (in my opinion) The Lens. There are other free patent search sites, but those ones are pretty good. Patents are specific for a jurisdiction so you could limit the scope to just the countries you are interested in. Start broad with search terms. This means fewer specifics. Be aware that you need to actually comprehend the claims to know what a patent is covering. Patent titles are often very general. You may want to search the patents assigned to the firm you know sells the product you are worried about. This doesn't guarantee finding a patent since it is possible the firm licensed the patent from someone else. Once you find a patent that seams relevant, look at the cited patents to find more potentially relevant patents. Remember patents expire so if you can find a patent more than 20 years older than it's filing date that is a good thing for you. Ultimately, determining freedom to operate is a legal opinion and having a good patent lawyer is recommended.