User blog comment:Harbumz/Introducing Vignette, Wikia's New Thumbnailer/@comment-1251315-20150212153753/@comment-452-20150213163413

http://vignette1.wikia.nocookie.net/central/images/2/20/Community.wikia.com_Template_Cc-by-sa-3.0.png/revision/latest/scale-to-width/100 << example image, content is irrelevant.

Open your browser console, and paste this: $("#comm-text-797391 img").attr("src", $("#comm-text-797391 img").attr("src").replace("/100", "/300"));

Obviously, this is just an isolated example, but if you give me a specific example which does not work for you, I will make it work.