Hello, Allison!
Welcome to
planDisney. Your question made me smile, Allison. I am so happy that character interactions have returned. I have a trip planned soon and I can't wait to dust off the autograph book as well!
You are welcome to use almost any pen that you would like and you'll see people use a plethora of different ones. I do like how a marker looks with its nice thick brushstrokes but oftentimes they do bleed through the paper and that can be unsightly. What I recommend using is any ink pen that you like that has a thick barrel and is retractable. A thick barrel is going to make it so much easier for characters with thicker hands to grab on to and the retractable feature is nice for the characters to be able to click up and down when they are using it so as not to get ink on themselves. This style of pen can be found a lot of places but you'll also see these all-over merchandise stores while you are at
Walt Disney World. This is typically where I'll pick mine up because I know it's the preferred pen. Plus, it's a fun little souvenir to take home when the trip is over that is practical.
If you do decide to go with a marker-style pen that bleeds through, consider putting a piece of paper between each page. That way, it only bleeds onto the back of each individual page. Then, you can glue a picture on that particular page to cover it up. I've done this before and it's worked out nicely because then the autograph book turns into more of a scrapbook keepsake that you'll want to look at for years to come.
I hope this helps with your decision, Allison. If you have any other questions before your trip, please feel free to stop back by and
ask me. I'm happy to help.
Have fun!
Jackie H.