This document summarizes two studies on Pressure Marks, a new pressure-based interaction technique for tablets that allows for concurrent selection and action using pressure-sensitive marks. The first study found that Pressure Marks are a viable interaction that participants could learn, with errors and task completion times decreasing over blocks. The second study found that Pressure Marks were faster than existing pigtail marking techniques. The document concludes that Pressure Marks show promise as an orientation-independent marking method and could enhance other marking techniques, but leaves open questions around complexity of marks, need for pressure sensing, and how browsing pressure marks may work.