Will an autograph smudge on a dust cover?

[Kestrel]

I was going to send my Life on Earth dust cover to Sir David Attenborough to sign but it's that kind of glossy dust cover and I'm not sure if pen will smudge, will it? And if it does is there any other sort of writing instrument I could buy and send?

[AlistairSaintClaire]

Don't worry, I think it won't smudge! I have a very glossy, shiny dust jacket signed in silver marker, and it's absolutely fine.
You can try some pens on other glossy material (like old photos or any packaging) to see if they word on glossy paper, or not.
But still I don't know how your cover looks like so I cannot give you a guarantee!