Maybe it was 85 and raining at Camp Perry or perhaps you were on your last string of fire and closing in on your personal best score. Regardless, you've had to deal with a wet or sweaty hand on your gun. Traditional wood grips generally deal with this issue by stippling a portion of the grip. A stipple is a surface, generally cut into the grip with a sharp tool, that provides some additional texture on an otherwise smooth grip.
Utilziing the exceptional detail possible with 3d printing, you can specify to what degree you would like your grip stippled. From a golf-ball dimpling to a wire brush in your hand, a range of surface aggressiveness options are available. See above for an example of a stipple of about a 4 on a 1-10 aggressiveness scale.
If instead you would like to stipple the grip yourself, I would suggest using a fine point on a soldering iron. It is tedious work, but the results can quite effective. See below for a soldering iron applied stipple.
Alternatively, you can go a couple of other routes. Jimmy, whose grip also sports a great paint job, used simple grip tape. Grip tape is cheap, removable and easy to apply.
Finally, some of my shooters on the college team I coach keep a rosin bag at hand. You can make your own with a zip-lock bag, some baby powder and a small square of cloth.
It doesn't matter if you're still trying to find the black, or have been a High Master for so long you look at a 9 as a tragic mistake, you're probably never going to be done working on your grips.