"The selected item level too low to maximize materia potential"

[HyoMinPark]

The stat caps aren't exactly hidden. When you have the meld window open you can see the stat caps for each item.

To piggyback, an example of what you would see in the meld window could be something like:

Vitality: 20/20 Strength: 20/20 Critical Hit: 0/20 Determination: 15/20 Direct Hit: 10/20


These aren't actual stats, but just an example of what you may see. Vitality and Strength are 20/20, so they are capped and you cannot meld any more of them. However, Critical Hit is 0/20, meaning that you can meld up to 20 points of critical hit materia into the gear. Likewise with 5 points of Determination and 10 points of Direct Hit.

White gear can be pentamelded, meaning you can put up to 5 materia in it. Note that only the visible slots you see on the gear are guaranteed a 100% success rate. There are other, advanced melding slots where the percentage for success is lower (i.e., not 100%). All of the gear you can craft may be pentamelded, but some gear only allow 1~2 melds, and some none at all. The game will tell you if you cannot meld a piece of gear.