between layers of paint, what grit sand paper am I supposed to use? and for wet sanding the clear coat, what grit sand paper am I supposed to use?

 

Passing on what I have read elsewhere For wetsanding purposes use a super fine grit like 1500 or 1000, if checking the packing or asking a clerk normally it states for wetsanding or wetsanding paper. For sanding you can start with 800 and move up to 2000, what you start with I would assume depends on how many coats are going to be used. Just make sure you evenly sand out the surface and allow enough drying time in between coats (overnight if necessary) .