This practice-led thesis is based on a study of the use of encased voids or bubbles in glass. The study is grounded in practice and draws out through antecedents in philosophy, psychology and epistemology, a methodology called Reflective Risk. It shows that through a rigorous analysis of practice, using video and personal reflection that new insights emerge. The study is framed by craft practice (the word craft here used as a collection of ‘genre’ of which glass is part). The thesis uses experiential learning as a tool and a means of understanding the practice of creating and controlling encased voids in glass in the context of contemporary applied arts practice. The framework, Reflective Risk, is constructivist in approach. It is based on Experiential Learning Theory (ELT), but it also draws on epistemological theories of tacit knowledge. The thesis shows that through an understanding of technique and material qualities, process can be deconstructed to reveal new insights. The thesis documents how an understanding ELT and a range of self-regulatory antecedents can influence the cognitive process of craft practice through praxis. The results of this study, on the one hand, are directed to glass practitioners and on the other, to provide a theoretical approach appropriate for the reflective practitioner working in other media by adopting a parallel method of enquiry.