Haven't used them yet but they are quite heavy and robust. I'm pretty confident they will do the job for sidewalk I'm planning to pour this summer in front of my residence. Pattern is pretty straight forward and don't get confused about comments stating the pattern is identical for all four colours. This is normal and the four colours just ensure you don't repeat same pattern throughout large surface. I purchased a can of coloured release agent and can't wait to start. Will followup with pix of completed project when done.