How we visualize our characters is an important consideration in fantasy role playing games. In some ways this image may be influenced by the particular set of rules we are using or the adventure we are involved in whether as a group or solo (see this post on Mesmerized by Sirens for a take on this) but our own personal vision of the fantasy always contributes. There are obviously many takes on this, from high fantasy to the very low. Most of the artwork produced for the big-name games these day tend to favor the high fantasy end of the spectrum.
For myself, I tend to view my delvers as rather rough and ragged individuals; a sort of dirty fantasy if you will as opposed to high fantasy. My delvers do not wear eternally shiny armor, wield enormous weapons that defy gravity, or even look clean. My personal fantasy world is deeply entrenched in the reality of the medieval world, and the medieval world was a dirty place; for most people at least. I'm often amused by illustrations of adventurers in dungeon or wilderness settings where they are completely clean, their clothes spotless, armor pristine, and weapons gleaming as though freshly polished. This is far from what I have in mind when envisioning my characters. They are typically coated in dirt, grime and blood (that of their foes and their own), their clothes are patched, ragged, and equally dirty, their armor is also patched, dented, and (if metal) has patches of rust, and their weapons are at least a little tarnished, kicked, and (often) bloodied. Delving is a dirty business. How clean can you stay crawling around a cave complex, a ruined castle, or ancient crypt? What is the state of you and your equipment after five or six battles with goblins, ogres, zombies, giant spiders, and a gibbering horror?
Of course when delvers return to civilization they can get themselves cleaned up and bandaged, buy fresh clothes, and repair and oil their weapons and armor. But this still does not fit fully into my vision of delvers. Considering their chosen occupation as well as the world in which they live, my delvers would never get too clean. After all, getting too comfortable would make it difficult to head back out and face a gruesome death. It's best to stay on the periphery of civilization. But even the civilized world is not that clean (at least in my settings), unless you're of noble birth or of the wealthy class. Such people seldom take on the life of a delver. Delvers may some day acquire enough treasure to afford fine clothes, a nice house, and clean living, but they'd likely retire from the dangerous profession of delving at that point and enjoy the quiet life of the wealthy.