Probably you left your painting for too long before you started painting it. Unfortunately, after a certain period of non-use, the paint can dry despite the airtight seal.You can try to apply the paint carefully with a few drops of water and then mix it properly. If it doesn't work the first time, try to repeat this procedure until the paint reaches the desired consistency again.Unfortunately, we are not able to deliver colors if the order is older than 2 months.