I've been using these 6x9 inch clear poly bags with adhesive seal: https://amazon.com/gp/product/B07X8C58BK Amazon ID: B07X8C58BK

I still use the paper sleeve with window for individual discs. Then bag those + paper inserts. I like those particular bags because they're consistently thin unlike zip-lock style bags so they pack nicely, and they fit most DVD paper inserts/cardboard sleeves except some multi-disc sets.