Flagstones Flagstone pieces are nature-made and therefore they will vary in size and shape Approximate thickness of pieces are 1/2"-1". Height and width of each piece are rounded up to the nearest inch. Recently however, you might have noticed that some of my newer art pieces appear to be perfectly square. I've found a local rock yard that sells cut flagstone pieces. My canvas is still nature-made and I will continue to use irregular sized pieces but will incorporate these cut ones as needed.   Click on thumbnail to view larger image. Artwork title and size are below main image.