Hey all, I work in advertising and marketing, so I'm not sure if this is the right place to ask. I have an idea, but I have no idea if it's feasible, and I figure that this might be the best place to ask. I'm looking to 'paint' something on concrete or pavement (like a parking lot) that would disappear (or become translucent) when wet/cold, but would be visible when dry and warm. Primary focus is on wet/dry, the temperature thing isn't as important. It doesn't have to be too durable - last a few weeks at most for my purposes. Paint, or decals would be ideal. Other ideas on how to accomplish it are welcome, but mustn't damage or alter the surface. Does that material exist? Thanks!