Sketching is of great value as a process, input, output and tool in HCI, but can be confined to individual ideation or note-taking, as few researchers have the confidence to document events, studies and workshops under the public gaze. The recent surge in interest in this sometimes-overlooked skill has manifested itself in courses, workshops and live-scribing of high-profile events – and a renewed enthusiasm for freehand sketching as a formal part of the research process at all levels. SketCHI aims to address both research interests and sketching practice in a combined approach to define, discuss and deliver theory and methods to a broad audience. As well as structuring high level discussions and collating information and resources, this SIG will allow attendees to practice and explore observational sketching on location around the conference, with feedback and encouragement from industry professionals. Finally, attendees will be encouraged to collaborate and form a research community around sketching in HCI.