The artworks of british impressionist painters must have a creation date. Whether you buy a canvas from a physical gallery or online, you must check the date mentioned. Also, you have to look for the signature of the artist. There are several cases of art forgery, and to separate a genuine from fraud the first step is to look for the genuine signature. If you are doubtful of it, then search online for the real signature image.
Visit- https://www.behance.net/gallery/122948203/Paintings-of-British-Impressionist-Painters