The 1000th Sheet of A4 Paper

Today marks the 1000th sheet of A4 paper I’ve used since I began university back in 2020.¹ My studying technique is writing what I’ve learned using pen and paper. All the theoretical knowledge, math, and most stuff that isn’t code belong on paper. Typing these ideas is less memorable compared to writing with pen and paper. Despite this, flashcards belong to Anki.

I was close to running out of paper, so I bought another 500-sheet stack. When buying paper, you’ll find there are a lot of options if you look closely. I want to write briefly about A4 paper types for writing with a pen from a consumer perspective. Quality Class A is really nice to write on. Quality Class C is okay at the end of the day. Since I don’t use that much paper, I think using Class A would be a good choice to write on. Here are the details:

• Paper Weight (GSM): $80~\text{g/m}^2$ is your standard copy paper, while $90~\text{g/m}^2$ is heavier and feels nicer. $80~\text{g/m}^2$ works fine.
• Whiteness (CIE): Higher CIE means brighter paper. I prefer around 170 CIE for better contrast. When writing with a pen, I really like 170 CIE. 145 CIE is your average white paper, and when you go down to 100 CIE, it’s noticeably duller. I thought about including an comparisonimage here but digital screens doesn’t do it justice.
  It is measured via a spectrophotometer that shines light on the paper.
• Smoothness: Well, you guessed it right—it’s how smooth it is. The smoother the paper, the more time it can take to absorb ink, which might lead to smudging if you’re not careful. 220 ml/min is good for ballpoint pens, but 170 ml/min feels nicer to touch.
  It’s measured via the Bendtsen method, where a ring is pressed against the paper and the air volume passing between the ring and paper is measured.
• Opacity (Ghosting): Higher opacity means less ink bleed-through. 93% is good for single-sided writing, while 95% opacity is good for double-sided writing. Usually, this isn’t a big issue as I mostly write using a pencil.
• Glossy vs. Matte: For writing, matte is usually better, and glossy is more for printing photos.

If you want to dig deeper, there is literature about its history, manufacturing, measurement, and more. But it’s not my expertise.