Seth Larson @ 2025-07-01

I really like QR codes. Recently I purchased a new sticky-note-like pad from a new local stationery store in Minneapolis. The sheets have a 10x10 grid and 2x10 grid.

I knew what I wanted to do, I wanted to create a QR code on a sheet. The smallest QR code (besides micro QR codes) is "version 1" which uses 21x21 pixels. We'll have to split the squares in half and then use some of the margin.

Version 1 QR codes can hold URLs up to 17 bytes long using the lowest data quality setting. Unfortunately https://sethmlarson.dev is 23 bytes long, so I'll have to improvise. I went with sethmlarson.dev instead, as this will prompt many QR code scanners to "search" for the term resulting in my website.

Note that a lovely reader informed me shortly after publication that indeed I can include my full domain name in a version 1 QR code by using all capital letters instead of lowercase. TIL that the "alphanumeric" character set for QR codes actually contains symbols for URLs like : and /.

Expect an updated QR code published after lunch today. :)

I created my reference using the qrcode package on the Python Package Index. Don't forget the -n option with echo to not include a trailing newline.

$ echo -n "HTTPS://SETHMLARSON.DEV" | qr --error-correction=L

I drew the corner squares (known as "position patterns") and then started trying to scan the QR code as a gradually filled in other pixels. Once I had drawn the "timing lines" between the top left and bottom left position I could see that my scanner "wanted" to see something in my drawing.

I continued adding the top timing line and data and then the scanner could start to see the whole square as a QR code. If you look closely I even made a mistake here in the data a bit, but in the end this didn't matter even on the lowest error-correction level.

Finally, my QR code was complete! Scanning the QR code was quite finicky because the paper was curling up off the flat surface. I could only get the scan to work when I held the paper flat. However, hanging the QR code from my monitor worked extremely well, even when scanning from a distance.

I hope this inspires you to try hand-drawing something on grid paper 🖤🤍 If you're looking for more grid-based inspiration, take a look at GRID WORLD, a web art piece by Alexander Miller.

Wow, you made it to the end!

• Share your thoughts with me on Mastodon, email, or Bluesky.
• Browse this blog’s archive of 178 entries.
• Check out this list of cool stuff I found on the internet.
• Follow this blog on RSS or the email newsletter.
• Go outside (best option)