For the Acaia Pearl, a portafilter will definitely fit. “Chopped” or “naked” portafilters fit best with the aerial heat pad in its normal position. Spouted portafilters can be used with the aerial pad flipped to provide a rest for the portafilter, as shown below.
The Acaia Lunar is not designed to fit a portafilter. However, we have come up with a solution with the portafilter weighing plate, pictured below. This magnetic plate is perfect for using the Lunar with a portafilter, or for pulling an espresso shot into two cappuccino cups.