If they are not dampened, hold between 5 seconds and 1 to 2 hours.
However, is not without reason on the photos instructions that they should be dampened. Then the results are much better: usually hold about 10 minutes, or - with veeeery good luck - to several days (!).
The problem: You never previously knows how long they will be liable. A marker, which still held earlier well, keeps even worse next time. So the best the glass watching all the time :)) or as another reviewer said, "The last forever, because you suppressed it but repeatedly, when you hold the glass in his hand." (Huh? Why does he want highlight it if it anyway keeps it all the time in hand?)
My suggestion: Spread homemade coasters. Your Coaster all look the same? Let your dog play with it before. You have a dog? Guaranteed somewhere in the neighborhood runs a rum. Or put your child on the same-looking coaster at: Put them just the coasters and your toolbox out. Children are creative. Or take your old CD collection as a coaster! She is still good for something. (The latter I have done. And in addition I booklets still a Creepy tuned. Did those things now bought time. And if they become detached from the CD, you can not fall off at least.)
