I purchased three pen organizers on Amazon each one with different count of pens it holds and layout.
BTSKY 160 Slots Colored Pencil Organizer
As shown above I have Papermate Flairs, Tul, Papermate Inkjoys, Midliners, Staedtler fine liners, Kelly Creates Brush pens.
Pencil Case Holder Slot – Holds 202 Colored Pencils or 136 Gel Pens with Zipper Closure
In this case I have Crayola Supertips 50 count., Staedtler Dual tips, Colore Colored Pencils.
BTSKY 200 Slots Pencil Case- Portable Oxford Fabric Pencil Holder
This is the largest of the three cases, I have Sharpie fine point art pens, Gelly Roll gel pens, Micron Fine Tips, Bic Intensity Fine line marker pens, Pilot Razor Point pens, Uchida Le Pens, Pentel Sign Pens Touch Fude Brush Tip, Stabilo Point 88 Fine liners, and Frixon highlighters and Pilot Precise V5s.