Systems, methods, and apparatus for a three-dimensional (3D)-printed vessel for wettability assessment of fracturing proppants are disclosed. The vessel includes a base component including a threaded cylindrical portion extending outward from a first side of the base component. The cylindrical portion has a particular thread profile. The base component defines a cavity sized to contain a proppant sample. A cap is configured to be screwed onto the threaded cylindrical portion after the proppant sample is injected into the cavity. A surface of the cap is shaped to flatten a proppant surface of the proppant sample. The cap is threaded with the particular thread profile. A pin is configured to be partially screwed onto a second side of the base component before the proppant sample is injected into the cavity. The second side is opposite to the first side. Other embodiments may be described or claimed.