How does skill point increase work with inspiration?

My JC was 88 and I recrafted some equipment gear and it proc to rank 4 and I recrafted it five more times and it proc to rank 5. I assume my JC went up one point for each inspiration proc. Would the same thing happen if the item was rank 2 and proc to rank 3? Do the mats have to be rank 3 for a skill increase proc?