Guitarist's Ripped Fingertips?

I play guitar at least three or four hours a day, and my fingertips are always ripped from thin torn calluses. Guitarists will know what I am talking about. My calluses are hard and comfortable, but I hate the rough feel they have because of the ripped layers I get after playing for an extended period. Any suggestions? I use a nail filer to smooth them out, but is there something else you would suggest?