I use a sharpie at work all the time and hate having them in my pocket. This is a simple way to have one on you all the time, and without it in it doesnt really get in the way.

I have used this for about a year and the clip holds very strong but the sharpie comes out easily. If you need it a bit tighter I can add some other models.

Simple quick print. 4+ perimeters works well.

Clips on to the hat around the sweat band on the inside of the hat.

I might upload this for other popular pens, and maybe some flashlights so you can really impress.

(Be carful hugging people with this on your hat.)