I got these calendar cubes from Baker Ross and distributed them for colouring. They were coloured beautifully, by people very much younger than me. We used my Copics and regular felt pens. They are on a coated board and there wasn't much difference in performance between the pens to be honest.
See the striped effect on the November and September sides? That's a Copic...it didn't blend well on this particular surface. The girls didn't mind; I certainly didn't...it's fine!
The boxes are pre-scored and easy to assemble; we used glue but it wasn't really necessary. One of my aides-de-camp used ribbon to string hers up for hanging - no doubt somewhere where she can easily see her busy life. One of them (there a five in a pack) was unfinished and I brought it home with me and dumped it on my desk. Some time later, I was out and about with my sister-in-law who made a passing remark about a family birthday that I was unprepared for. Saved me some embarrasment and also gave me a use for the unfinished calendar boxes. I cut them into individual months, marked dates on one side and names in date order on the reverse of each month. Punched, coralled with a book ring and dropped it in my handbag. Nice, on-the-go, non bulky, disposable without conscience birthday book.
Don't tell me I've a diary. I haven't. Don't tell me I could use my cell phone. I could. But I don't, it's for calls and messaging. My life may be in my handbag, but it's not on my 'phone!
This works, and it gave my test audience some fun. Win win!