Weck jars are my go-to for storing sauces, condiments or leftovers. They come in such a wide range of sizes and shapes, that I can use the smaller sizes when I make mustard or ketchup, the tall size is perfect for pickled vegetables, and the large size works well for making limoncello. The glass is sturdy, and the clip-on lids come with a rubber cushion to seal tightly. Plus, I love the look of their modern-industrial-european yet homey styling.