DISCLAIMER This procedure works very well on the Grips I manufacture. It may NOT work on other manufacturers Polyurethane. Do a test on the back of the grip and procede at your own peril. I have a way to age the grips further that you can do at home. You are in control and it is fun to try various "looks" to the age of the grip. The good news is that it doesn't damage the grip and is completely removable if the results aren't to your liking. All it takes is some paper towels and a small amount of Burnt Ochre or Gold Sienna acrylic water based paint, available at any Wall Mart store in the crafts section. After final sanding and before any wax etc is applied to the grip, place a drop or two of the color on a folded paper towel. Gently rub the color over the face of the grip. (The longer the paint sits on the surface the darker it will be in the final stages, a little is best, you can always add more). Buff away the excess with another folded towel. Want some streaks, OK, just add a tiny drop of brown to a small amount of your base color. Apply the mix to a Q-Tip and streak away. When you are happy with the look, "Burnish" (rub the surface quickly and with some pressure) the grip with another folded paper towel. Sit back and admire your creation. Not good enough?? OK, sand it off with some 3M 400 grit wet/dry sandpaper, used wet, available in any DIY store and start again. Once you are satisfied, a thick coat or two of a good quality paste wax will protect the finish. The wax can be applied with another folded paper towel and the last coat "burnished" for a very nice gloss.