These are one of my favorite tools, no matter what grade I'm in. They're fantastic for art projects and free paint in the makerspace or at the easel, or to use in centers for marking high frequency words with fluency games. I've found just as much use for them each year, whether it's been PreK, kinder, 2nd... all the kids love them. They will mark lighter tables (magic erasers usually do the trick) and leave some staining on clothes, but they mostly wash out. Definitely show your kiddos how to dab, versus squeezing or rubbing. The felt tips will tear if they're used overzealously.