A fine or brush tip are excellent choices as long as the ink or pigments are archival.
A few pens out there that will do a great job and are used for professional grade:
- Copic Multiliner SP
- Rotring Rapidograph
- Sakura Pigma Micron
- Prismacolor Premier Illustration Markers
- Uni Pin Fineliner
- Faber Castell
- Staedtler Pigment Liner
- Sharpie Permanent Marker fine tip or brush tip
Ballpoint or gel pens can be used if your hand is more used to it, but make sure they are archival and test first on the paper sample included, or on the back edge of the canvas print if applicable.