I've been on the hunt for the world's best pen for the Mighty + Bright calendars, and I'm happy to say that I found it in Germany. Staedtler's super fine wet erase pens are clear and smudge proof, and come off with a damp cloth. 

We recommend three different pens for different use cases:

• Dry erase: for temporary, easy-to-erase appointments/notes. This can be easily wiped off (even accidentally).
• Wet erase (this pen): wet erase is a great middle ground between dry erase and Sharpie — it can easily be removed with a wet cloth, but won't smudge like dry erase.
• Sharpie: while considered "permanent," you can remove Sharpie with alcohol wipes or hand sanitizer. It's good for weekly appointments that stay the same each week. When writing on magnets, these aren't easily removed.

Wondering what's included? See “What’s Included” below.