Today i received my premium card. After the initial chip + PIN payment I wanted to sign the card as i always do.
But i just couldn’t.
The pen, that worked on the standard Visa and Maestro, wouldn’t write on the signature field unless i pressed so hard that the signature basically was embosses.
I notice that the other cards had a different sticker for the signature field (visa having the best in my opinion).
Has anybody else encountered something similar?
Actually, I’ve never signed a prepaid card.
Since your Revolut prepaid card gives any person who has it full access to all your funds (unlike a real prepaid card) it would be wise to sign it.
It doesn’t make any difference everywhere you use chip+PIN or contactless.
However, i am not sure how this behaves with swipe payments
I think a good way to sign a card is using a thin permanent marker. There are also some pens that write on more surfaces - like the awesome Space Pen™. If it writes in space, it will write on your card. 
normal pens rarely work on any cards properly. We use the medium tipped permanent markers.