These are fantastic for kids, my 5 year old son loves collection rocks and people's whenever we go visit somewhere and once back home he loves to decorate them but he just used normal felt top oens which wouldn't last after a certain amount of time it would just get rubbed off, I've was searching for something a bit more longer lasting and cane across these coloured pens which are fantastic they work really well the colour is vibrant and they stay on the stones for a very long time so now I have a very happy 5 year old.