Warning, they are erasable because the friction (frixion, lol) heats the ink causing it to turn clear. So be careful not to leave your journal in your car or another hot place or you might just lose all your notes.

I have this multi-color one straight from the 90's and I love it. https://www.amazon.com/dp/B00IPD3KEM/ref=cm_sw_em_r_mt_dp_U_uUDUDbCZG70VB

This is what I use! AND it's erasable! Pilot Frixion 4-Color... https://www.amazon.com/dp/B00IPD3KEM

Love that you got the stamp. It's the best!