There is at least one grader at ANACS that wears/wore gloves. A few years ago I put in a submission of 10 coins to be graded on one of their specials, and they all came back with a latex smudge on the obverse field, in same position. The grader, or maybe an assistant, pushed my coins into the plastic sleeve with a gloved finger, and they forever have this smudge. That was the one and only time I have sent coins in for grading. I believe it was noted before, but it is indeed proper to wear gloves when handling a proof coin. The edges of a proof coin are considered to be (nearly) as sacrosanct as the faces, so never touch a proof coin with bare hands, no matter how clean. It "just isn't done".