Balls Form Knit explores the relationship between spherical objects as a filling material and knit to design transformable objects that offer an alternative perspective on what anatomical support can be, based on bold interaction. The expressive possibilities of weft knitting have been investigated from the perspective of generating form using the tension created by the filling. The elevation of the textile and fillings role from passive to active within the context of seating objects has been the starting point for this work. Both filling and knit have been worked with simultaneously to let them contribute to the expression of the design and let the meeting between their properties influence the form and the way an audience interacts with the objects. As a final result, the collection consisting of six textile objects presents ways in which different knit techniques and filling can be combined to create transformable objects that offer different interactions and supports for the body. Balls Form Knit engages the user to interact and be playful while finding support in a way that is intuitive and accessible.