One of the very first decisions we made was - WHAT PAPER we wanted in our Encouragement planner. I love using felt tip Paper-mate Flair's and I wasn't creating a planner I couldn't use one in.
Every printer I interviewed suggested a cheaper quality paper to which we said NO to. We are all about quality. I will not design you something I do not believe to be quality. End of story, non negotiable. Yes I am particular but excellence isn't cheap and these days it is harder and harder to find in products. It is true you get what you pay for, so, we paid for good paper.
As a result you should be able to use your favorite gel, ball point, and FELT tip pens. The only 'pen' we do not recommend is an alcohol based ink or a Permanent marker. Sharpie pen yes, Sharpie marker that looks like a pen - NO. With any pen we have not mentioned in the above video, you can always do your own pen test in the back of your planner. We have added several extra pages for just this sort of action.