This chapter details a method to support designing specifically with recycled materials, which is a single niche of the broader Sustainable Product Design. To achieve circularity, materials must not only be recycled, but these recycled materials should also effectively be used in new designed products to enable a new loop. The ambition is not to downcycle and dump recycled materials in products, but to consider these new material streams as valuable materials with specific characteristics. In contrast to Design for Recycling, a well-known strategy to increase the recyclability of products at their end of life, Design from Recycling is a relatively new approach within the concept of circular economy, which examines to what extent a new product can be produced from an existing flow of recycled polymers, and the design specifications this entails. The chapter explains how design specifically with recycled plastics can be optimized from the perspective of the material rather than that of the product. The new recycled materials are characterized not only from a technological perspective, but also from a user-centered perspective, which offers a new insight in defining the identity of the various recycled plastics and enables them to be implemented for their ideal future application. The method supports both designers and engineers in the identification of the material identity of a new recyclate and the search for further implementation.