CHARACTERISTICS OF THE PERFECT PEN
Smearability. I like to draw black outlines and then quickly add shadows and color fills. Because I like to work quickly, the black outlines are not always dry when I add color. If I add yellow on top of black, I can sometimes get some wicked smears that make everything look murky. There are several types of black markers, but a few common ones are alcohol-based ink, water-based ink, and pigment ink. My experience is that the alcohol-based ink (i.e. Sharpie, Bic Marking Pen, Prismacolor, Copic markers) smear the least, water-based markers smear the most, and pigment-based markers are in the middle. I did an extensive black pen test to find the least smeary black marker.
Toxicity. While the alcohol-based markers are fantastic in the variety of nibs and non-smear categories, they are terribly stinky and feel toxic to me. They also bleed through the page. I occasionally use Sharpies to draw sketch notes, but not often because they make me nauseous after about 15 minutes. I gave all of my Prismacolor markers away because I couldn’t even tolerate them for 10 minutes. If you can tolerate the stink (or work in a well-ventilated space), graphic designers and illustrators LOVE Copics and Prismacolor markers.
Sustainability. Most markers are disposable. You throw them away when they run low. Some markers are refillable, but these are rare. Water-based markers are probably the most environmentally friendly option because they are non-toxic. The downside of water-based inks is that they are not as archival as other markers (they fade in sunlight).
Cost. If you are drawing sketch notes, you probably won’t go through markers so fast that cost is going to be a big issue. I draw about 50 square feet of sketch notes each month and I go through about 1 black marker and 1 color marker each month (on average). However, if you draw a lot of large wall charts, it adds up. You can shop around to find the best deals on markers and pens (because different places have different sales at different times). I buy markers at my local art stores and also shop at DickBlick.com JetPens.com Neuland.com and Amazon.com.
PERFECT PEN RECOMMENDATIONS: SKETCHNOTES
Black outlines. I go back and forth between several black markers. I haven't found the best ink-nib combination, so I oscillate among four types of markers.
Colorful markers. Again, I have two types of markers that I like for coloring my sketchnotes. I usually color and add shadows with a brush nib marker. I used to use fine nib (~0.5 mm Triplus Fineliner pens from Staedler) to draw colorful sketches alongside my sketch notes, but my style has changed over the years.
PERFECT PEN RECOMMENDATIONS: WALL CHARTS
Black outlines. My go-to markers for black lines on wall charts are Neuland Outliners. Period. They are just amazing markers. I love that they are refillable and non-toxic and don't smear. Honestly, I do not know how they do it, but the Outliner ink is amazing. It reminds me of India Ink (and may be!).
Colorful markers. I alternate among a few types of markers for wall charts, but will only discuss a few here. If you don't want to order fancy markers, you can get a lot done with three types of water-based markers that are available at most office supply stores: Crayola Multicultural Markers (for coloring people), Sharpie Flip Chart Markers, and Mr. Sketch (a.k.a. smelly markers). The Sharpies and Mr. Sketch are easy to find in bullet nibs, but search for chisel nibs because I have seen them.
Everyone has personal preferences when it comes to art and office supplies. Try a few things out and let me know how it goes!