Erasable gel ink pens in lots of different colors.
Working on paper still beats tablets etc. sometimes, and instead of crossing out stuff and trying again, you erase and overwrite – looks much cleaner, even if this was your very first draft / rough diagram / whatever. Instead of copying / re-writing the whole thing a half-dozen times or more to get a final clean version, you copy maybe once, at most twice, often not at all. (You just erase small mistakes that happen while making the clean version, instead of starting over yet again.)
Beats colored pencils by a wide margin, both in handling when writing/drawing as well as in ease of erasure. (The ink becomes completely invisible when heated, no need to scrape pigments out of the crevices of the paper / abrade the paper surface.)
Muji (the “Japanese Ikea”) had great ones, but they got rid of most colors (no more green/cyan/purple/…, only black/red/blue.) Luckily, lots of others are producing them now, so I can get new ones when mine (and their refills) finally run out.
My only warning: If you’re writing double-sided in a notebook with thin paper, don’t be too vigorous when erasing. Normal corrections are no problem, but taking out a whole shaded diagram might also erase parts on the back. Other than that, while I’m not sure how long-term stable these inks are, my 5+ year old notes still look fresh. (I still made backup photos just in case…)
Erasable gel ink pens in lots of different colors.
Working on paper still beats tablets etc. sometimes, and instead of crossing out stuff and trying again, you erase and overwrite – looks much cleaner, even if this was your very first draft / rough diagram / whatever. Instead of copying / re-writing the whole thing a half-dozen times or more to get a final clean version, you copy maybe once, at most twice, often not at all. (You just erase small mistakes that happen while making the clean version, instead of starting over yet again.)
Beats colored pencils by a wide margin, both in handling when writing/drawing as well as in ease of erasure. (The ink becomes completely invisible when heated, no need to scrape pigments out of the crevices of the paper / abrade the paper surface.)
Muji (the “Japanese Ikea”) had great ones, but they got rid of most colors (no more green/cyan/purple/…, only black/red/blue.) Luckily, lots of others are producing them now, so I can get new ones when mine (and their refills) finally run out.
My only warning: If you’re writing double-sided in a notebook with thin paper, don’t be too vigorous when erasing. Normal corrections are no problem, but taking out a whole shaded diagram might also erase parts on the back. Other than that, while I’m not sure how long-term stable these inks are, my 5+ year old notes still look fresh. (I still made backup photos just in case…)