This gem is meant to be used with bootstrap-sass. It gives you complete scss versions of bootswatches for use in your Rails asset pipeline, just like bootstrap-sass gives you scss version of bootstrap itself. When using bootstrap-sass, it's recommended to avoid sprockets in your stylesheets. In order to do that you simply rename your application.css file to application.css.scss, remove all sprockets comments, and instead use sass @import commands. These commands are smart enough to fully support asset pipeline load paths, thanks to sass-rails gem.