Nice experiment &exploration with the rain coat project...I'll bet the kids
had a blast.
Actually...I call them "watercolor" markers for the sake of the kids so the
capability of the "washable" markers stays prominent in their minds. I buy
the large Crayola Washable marker eight color pack set each year.
I also teach all the kids K-12 to use them with water and make brilliant
color wash because inevitably every year there are classes of kids that want
to make posters to support athletic events, etc., You all know how fast
makers get used up filling in bubble letters. However, by teaching the kids
to make the letters with a light source in mind, create shadows with cold
colors to fall on other letters and turn it into a project...they learn
something about painting, color & light, and I win by the markers being
conserved and lasting throughout the year!