Ever since Sketch Libraries were released in version 47, many people have been asking how to create a custom thumbnail preview that appears in the Preferences panel for their own Sketch Library files.
I’ve created a ‘template’ Sketch file that has the preview artboard already setup so you can quickly get started creating your own preview design. The free download also includes instructions on how to include the preview in your library file.
This template was inspired in part by Stewart Curry’s article “Customising the Sketch Library Preview Image — beta”. One key difference of this template, relative to the article, is that I’ve used an artboard that is @2x the preview size. This appeared to create better image quality on retina displays than a proportionally larger design & has the advantage of being easier to preview at 50% (target size).
Grab the file from github and use the issues tab to report any problems or feature requests.