As artists and toddlers have long known, paints can provide lots of entertainment. But, not every part of the process is fun: Watching paint dry is synonymous with boredom, like watching the grass grow.

It’s almost too bad, because there’s where the magic happens. The (usually) liquid paint drying, and becoming solid, is what gives the art (or school project, or bedroom wall) its longevity, its permanence. You can erase pencil and even some inks, but dried paint is there to stay.

That