Sin Titulo is a mystery webcomic by Cameron Stewart, following the supernatural experiences of protagonist Alex Mackay. Launched in 2007, the webcomic completed its run in 2012 and got a Dark Horse Comics print publication in 2013. Sin Tutlo won a Joe Shuster Award in 2009 and an Eisner Award in 2010.
The webcomic Sin Titulo follows protagonist Alex Mackay, who, at the start of the story, discovers a photograph of an unfamiliar woman in his grandfather's possessions and feels compelled to hunt her down. This leads him to an underworld populated by mysterious and strange concepts, such as an eerie laboratory and a femme fatale. Lauren Davis of Comics Alliance described Sin Tutilo as a "noir fantasy": though it suggests the existence of science fiction concepts such as interdimentional travel and "shared cognitive space", many of its visuals are akin to those of a detective novel.
Sin Titulo was launched by Cameron Stewert as a webcomic in 2007 and eventually finished in 2012. Stewert did the writing, illustrations, lettering, and coloring for the work all on his own. The webcomic started as an "exercise in improvisation", its ambiguous title Sin Titulo literally meaning "Without Title" in Spanish. Many ideas for the story coalesced halfway through, when Stewert got a stronger grasp of what the webcomic was about. In 2011, Sin Titulo went on hiatus for almost a full year, keeping its readers in suspense.
Stewert told Davis of Comics Alliance at the New England Webcomics Weekend in 2009, when Sin Titulo was still fairly young, that the webcomic is inspired by a disquieting experience he had as a child; one he's never been able to explain. He told Davis that he did not want Sin Titulo to turn out like the television series Lost, which was still airing at the time and which disappointed him for not answering all of the questions it set up. Though Stewert did not intend for it to be an autobiographical work, many aspects of the webcomic are based on his own experiences, including the sudden death of a neglected grandfather.