I don't think there is a perfect marking pen or pencil. I have tried a lot. I did a guild presentation on it. I did find that with several different methods I tried, blue seemed to be the hardest color to remove. I tried all colors of Crayola markers and a set of colored pencils I saw recommended. I used a bunch of different fabrics. On a few fabric the blue didn't come out. I tried ironing over them and not ironing.I used the blue water erase on a project that was heavily quilted. The marks were only there for 2 days. I had a terrible time getting them out. I have never tried the Hera markers. I sure wish there was something that worked for everything.