If you look at the non-solarpowered website, it turns out that TypeKit is serving a 830,8 KiB fullcolour PNG file. AAARGH. No wonder that they think they need to use dithering and such if that is their baseline.

I tried testing some variants and made a static HTML gallery on neocieties[1]. TL;DR:

- cleaning up the photo before filtering it makes a huge difference in image quality and compression.

- quality 80 JPG is 86,6KiB in color, 70,9Kib in grayscale.

- quality 40 (which is ugly but still has readable text) uses 44,8KiB and 37,8Kib respectively. The latter looks a lot better than the dithered image IMO.

- similarly, the grayscale PNG with pushed shadows and positioned dithering has readable text and contains significantly more detail at 4 colors and 38,7KiB than the 16-color 42,4KiB image on their server.

[0] http://www.lowtechmagazine.com/2018/09/how-to-build-a-lowtec...

[1] https://blindedcyclops.neocities.org/low-tech-image-tests/ga...