Goal today: bleed the rear hydraulic brake on a neighbor's gravel bike — lever had gone spongy enough that full-finger pull gave her almost no modulation on a descent. She's planning a group ride next weekend and asked me to look at it before then.
The brake is a Shimano GRX 810, mineral oil system. I prefer mineral oil over DOT fluid because it doesn't strip paint and I stopped labeling rags for that job years ago. Pulled up the Shimano procedure I keep printed in a page protector in the binder above the bench — I've done this brake three or four times now, but I still read it through before I start.
Removed the rear wheel, hung the caliper level with a rubber band around the rotor slot.