I haven't seen how it's done today, but I remember my grandparents canning and they used (reusable, IIRC) rubber gaskets like these: https://images-eu.ssl-image

I haven't seen how it's done today, but I remember my grandparents canning and they used (reusable, IIRC) rubber gaskets like these: https://images-eu.ssl-images-amazon.com/images/I/41ANtsDx7tL._AC_UL600_SR591,600_.jpg https://images-eu.ssl-images-amazon.com/images/I/41ANtsDx7tL...