Venous Materials is a novel concept and approach of an interactive material utilizing fluidic channels. We present a design method for fluidic mechanisms that respond to deformation by mechanical inputs from the user, such as pressure and bending. We designed a set of primitive venous structures that act as embedded analog fluidic sensors, displaying flow and color change. In this paper, we consider the fluid as the medium to drive tangible information triggered by deformation, and at the same time, to function as a responsive display of that information. To provide users with a simple way to create and validate designs of fluidic structures, we built a software platform and design tool UI. This design tool allows users to quickly design the geometry, and simulate the flow with intended mechanical force dynamically. We present a range of applications that demonstrate how Venous Materials can be utilized to augment interactivity of everyday physical objects.