Sometimes, golf equipment makers don't introduce new equipment because it has a particular benefit to the player. Sometimes, they release equipment because it just looks cool.
The latest example of this comes from Parsons Xtreme Golf, which has released a new black Xtreme Dark finish for its 0311 and 0311T irons and wedges. Of course, the club line known for $700 drivers and $2,500 iron sets wasn't going to produce the finish on the cheap, claiming their process costs six times what it takes to produce the typical PVD finish you'd find on irons and wedges.
Technically called DLC, which stands for Diamond-like Carbon, the Xtreme Dark finish is achieved through a three-layer process, using a chromium base, a carbon-chromium midlayer and a high-carbon top layer. The finish, just 3/25,000ths of an inch thick, is applied on the clubhead surface using something which Golf Digest describes as "a closed-field, unbalanced magnetron sputter ion-plating system.” That just sounds expensive. But the idea is that the finish actually makes the clubface harder, meaning the finish won't wear much over time.
The finish, available in limited quantities, will add $100 to each iron or wedge in a PXG 0311 set, meaning each iron will cost $400. Then again, if you're shelling out for a set of PXGs, at that point, money isn't much of an object.