ak interactive mix n ready jar packA set of four empty jars and four blank labels. Each jar has an airtight seal which is crucial to maximizing the shelf life of your custom paint blends. We recommend purchasing a set of pipettes to accompany our jars so that your paint blends are precise and accurate each time. Airtight Seal: Each jar has an airtight seal, which is crucial for maximizing the shelf life of custom paint blends and preventing them from drying out. Durability: The jars