1px Border Gap in Isotope Portfolio

Having the same issue that is referenced in this thread > https://kriesi.at/support/topic/1px-border-between-images-portfolio-grid/

Apparently there is a workaround, but I’m not certain how to implement (which classes / where). Could you have a look at this post from the Isotope developer and let me know what classes to assign his workaround to?

This is the CodePen example of the fix : http://codepen.io/desandro/pen/ca538fd8e2fbcb2416918099a6fcfdad/

Here’s the main github thread : https://github.com/metafizzy/isotope/issues/1056

Thanx!