This did not work for me.
I had used the instructions – “directly to the frontend.css file found at wp-content > plugins > jigoshop > assets > css”.
The source folder was the public_html/wp-content/plugins/jigoshop/assets/css.
I also applied it to my Appearance\theme options\general tab\custom style (css). (not sure this was the right place)
Version we are on:
Jigoshop Version: 1.11.3
WordPress Version: 3.9.2
Platform:
PHP Version: 5.3.2
MySQL Version: 5.0.96