Within most design domains, even though the term 'sketch' can be ambiguous and vague nevertheless sketching is acknowledged as playing an important part in the design process, carrying valuable information within the conceptual phase. This study confirms the importance and significance of sketching in the context of Automotive Design; the automotive design process is compared to design processes more generally. The subjects of the investigation were 9 automotive design professionals and 55 students in United Kingdom and Malaysia. The range of sketching techniques from professional designers is discussed and the study demonstrates that tacit knowledge and the understanding of automotive profile has a significant effect for designers' aptitude for sketching. The research identifies sketch types used in the conceptual stage of the design process: a distinction is made between thumbnail sketch, rough sketch, memo sketch, idea sketch and concept sketch. Investigation was conducted via sketching tasks with professional designers. Video observational analysis was carried out to complement protocol analysis to excavate the implicit sketching process by looking at a different aspects such as medium used, left/right hand, line repetition, sequence of activity, sketching angle, automotive component detailing, shadow line, duration of activity, size of sketch output and overall activity , with the. results documented and discussed. Professionals and students al~e regard sketching as the central signifying skill in automotive design, and beIi.eve that it is distinct from sketching more generally: this has led to a sketching convention characterized by few viewing angles and a 'strict sequence of sketch development, 3tarting with the wheels. At the end of the research, some recommendations relating :0 an understanding of 'theory of sketch\ approaches tl? s~etching in the early ~onceptual phase, and the understanding