Common trap when it comes to Materia melding

[The_Last_Dragoon]

Whenever you meld materia, not only do you have to be sure that the item level is high enough to actually hold the materia, but there is an internal cap for every upgradable stat in each item. When you meld, it will show a info box with the "effective amount" of points in that stat which will be applied to the item. Any extra points won't be applied regardless of how much materia you throw at it.

Let's say the internal cap for craftsmanship on a particular item is 4. Even if you use a Craftsman's Competence IV materia (+6) it will still only apply a +4 bonus. There are even some items that can't have certain stats upgraded at all, and yes it hurts when you meld a 40-80k piece of materia to a piece of gear that only gives a +1 or +0 bonus for it since it both ruins the materia and the piece of gear.

As a basic rule of thumb, try to read the entire info box and if you're not getting the full benefit from your rank IV materia, then it may be wiser to use a lower rank so that it doesn't hit your wallet quite as hard.

[Urthdigger]

Side note: Those maximum amounts are the same for every item of a given level and slot. So, all level 40 bodies have the same strength cap. The issue is that these caps are for the TOTAL stats, including those already on the item. In the case of high-quality battle items, they're typically already at the cap, so there's no point in adding materia for stats already on it. Instead, add secondary stats like crit or determination to slots that don't already have it.

Gatherer/crafted gear is the exception though. Even high-quality gear won't be at the cap for the stats on it, so you can push them further.

[ruskie]

Also it doesn't ruin the item. You can get all the materia removed at the goblin in central thanalan. Also not really a common trap. The game generally explains this hehe.

[Erendis]

It is only the trap for the people that do not read the instructions....

[Bixby]

It is only the trap for the people that do not read the instructions....

So, like OP said, a common trap.

[Niwashi]

As a basic rule of thumb, try to read the entire info box and ...

That's a pretty good rule of thumb in most situations.

I remember quite a while back some people were putting together a list of what the caps were on a lot of the top-end gear (though at least at the time, they hadn't extended it to lower level gear yet). The game will warn you if you try to meld a piece that won't be fully used, but (particularly when you start looking at the costly high level materia) it's nice to know before you even buy a piece that you won't be able to fully use. Anybody have a link to that stat cap info?

I post I made on the same topic a while back:
http://forum.square-enix.com/ffxiv/t...gear-stat-caps
as mentioned in there, there are at least some pieces (admittedly a low-level crafter piece in this example) where you can add more of the stat that's on it anyway, but cannot add a stat that's not already on it. So even that common pattern Urthdigger mentioned can't be relied on in all cases.