I got a new rod last week - a new 5 (and no, it's not an HT, because Paul is firm in his belief that 4 (which doesn't exist) is the new 5. And he may very well be right, but in my trout fsihing, I can't (well, I *could*, but I won't) get by without a 5-wt. It's my preferred line weight for stillwater. It's light enough to present small dries well, and yet, just that bit more backbone that the 4 when it comes to distance and handling sinking lines. The latter most likely being my main reason for choosing a 5-wt - not least because it's hard to get a good selection of sinking lines for a 4-wt.
But - it's about cork handles - and in this particular instance, my new 5-wt. Cork is awesome - the one and only handle material for me. Cork feels great, lets the rod flex deep and provides a good grip on the rod. And it attracts a very nice patina with some use.
When I get a new rod, I always treat the cork handle with U40's Cork Seal. It's a thin, polymer solution (milky white in the jar) that you simply brush on a clean handle (do wipe off the handle with a clean fleece cloth when you remove the plastic prior to coating it). Apply a thin coat and allow to dry for a few hours and you're good to go.
You don't feel it all, the cork still gets a nice patina, but is does protect the rod handle from the worst dirt and grime and makes it easier to clean the handle every now and then, should you be so inclined. And you don't really see it either - it darkens the handle ever so slightly as you apply it, but it's more or less invisible. It also seem to help keep the fillings in place.
Some people don't care, but one good argument is that a nice handle helps keep the re-sale value up!
Have a great week!
PS - as far as I remember, the above picture is the treated handle, the attached picture up in the corner was taken pre-treat.