Perhaps most importantly for anyone out there planning to go full Leslie Knope on these is that they're designed not to bleed through thin pages!
Promising review: "I bought these pens during quarantine, not expecting much, considering they are quite inexpensive. I've used well-known brand marker/pens in the past, and didn't want to pay much for markers I'd use for coloring. I was concerned about the tips bending or bleeding, but I was completely wrong and am very satisfied with this product! They do not bleed, and the tips are strong and thin. I use these pens for coloring, hand lettering, and note taking, and they're exactly what I was looking for! The only regret I have is that I did not order the larger pack with more colors!!" —Michael Fanizzi
Get a set of 18 from Amazon for $8.09 (clip the "10% off" coupon on the product page for this price).