So im using Posca markers for a school art project, but the blue paint from the marker keeps cracking when t dries. Any idea on how to stop it from doing that? Even the re-coats crack.

Don't put so much of the ink down, it cracks because there is to much ink.  So go lightly over what you need to do.  

Explanation:

The more ink you have the longer it takes to dry plus also it will crack because the in shrinks when it drys so put less for less cracking.

reply back saying, “ that’s no excise periodt “