Why does water leave a mark?

Question

Last week I put my granddaughter's cup full of water in my cotton shopping bag and it completely emptied out. It went through the bag onto my car seat. My question is why has it left a stain on the seat, when it was only water?

Answer 1

maybe she'd been to local doctor and being old misplaced her urine sample cup with one of water?

:-D

Answer 2

Could it have mixed with something in the bag, or even the bag's color itself and then stained your seat? What does the stain look like?

Answer 3

well when it leave marks on material it is because the dye in the material hasnt been set properly. Then as the water washes outwards it takes the dye with it that then collects as a dark ring where the water stops. this effect is called chromotography. however, when water leaves a mark on windows or taps etc when it dries that is the residue of the salt and limescale in the water

Answer 4

Distilled water would not leave a mark , its is the minerals in the water that left the stain