Submission + - E-Ink badges used at Dutch hacker camp SHA2017 (sha2017.org)
From the article:
"If the ESP32 is the heart of the badge, the beautiful E-Ink display is definitely its soul. At 296x128 pixels, it will be easily readable at moderate distances and, a first, readable in sunlight! Officially it's a 1-bitmonochrome display, so black and white only, but our team already has a greyscale hack working which uses the nature of e-ink to our advantage."