Is the Dark Mark always visible?

[sunnyskywalker]

It’s a common assumption that the Dark Mark is always visible on a Death Eater's arm, like a Muggle tattoo, and so Death Eaters must never, ever roll up their long sleeves. (I suppose this means they can never go swimming again, unless it’s at the Annual Death Eater Picnic.) Everyone knows about it, so characters might get suspicious if friends suddenly start taking unusual care about keeping their sleeves down. Romantic liaisons might end abruptly in shattering discoveries.

But does canon support this assumption?( Read more... )