Clean build plate and brim are advised!
Also print multiple at once so each layer of each piece has time to solidify before the next one is set on top.
Additionally, the color can be swapped at 6.6mm to make the 1x1 brick more distinguishable.
I tested printing it with a 0.2mm and a 0.4mm nozzle in PETG.
The author remixed this model.
Merged the 1x1 LEGO Brick with a Presta Valve Cap.