IML stands for "In Mold Labeling". IML is a widely used technique for applying labels or images to plastic containers or products that has replaced traditional adhesive or heat transfer labeling. With IML, the labels actually become part of the plastic product they are being applied to.
Printed on a special substrate, the labels are placed in an injection mold and held in place, usually by suction, and become fused with the wall of the product when molten plastic is injected or extruded into the mold. The label conforms to the shape of the molded product. This saves time and expense, since no additional work is needed to apply a label or decoration to the product after it is removed from the mold.
IML provides a cleaner look, lasts longer, and eliminates production steps. And, with IML, labels will not peel off, as they are "part of", not "on", the container.