We send all of our tickets in blank, windowed envelopes – the envelopes don’t mention Ticketmaster at all, not even in the return address on the back. It's worth keeping in mind though that there might be logos on the tickets themselves, so there’s a small chance this might be visible through the window on the envelope.
If you’re worried about spoiling the surprise, we could always send them to a different delivery address – more info on that here!