In mould labeling (IML) allows manufacturers to save time and money by integrating the labeling process directly into the forming process. This one-step approach offers big advantages over traditional decorating methods like pad and offset printing, shrink-sleeve labels, and pressure-sensitive and glued-on labels, all of which require secondary operations.
Improvements in output and labeling technology have helped thermoforming in mould labeling (IML) emerge ready for faster commercialization. This follows several trials over the last two decades. unlike the super speed with which injection moulding adopted IML, thermoforming has been under stress to address several important limitations in machinery and labeling technology. This has hampered IML�s penetration into packaging since the early 1990s.
The slow and steady pace of development efforts began with Germany�s Illig and Gabler introduction of the first thermoforming IML systems in the early 1990s. Until that time, IML had been limited to form/fill/seal machines with a secondary trim station. Italy�s OMV Group introduced an IML system at the K-98. Despite limited commercial success so far, the interest seems poised to catch up, particularly in Europe, mainly due to recent progress in productivity and lower costs for labeling that have finally made the process cost-effective.

Because a moulded-in plastic label becomes part of the product, contributing stiffness and strength, thermoformers can save upto 20% in polymer material cost by light weighting containers with IML. If the label is of the same material as the container, IML also offers recycling advantages over paper labels.
Labels used for injection moulding IML offered poor adhesion in thermoforming due to the cooler temperature of the sheet and much lower pressures involved.
Coextruded multi-layer PP labels with a layer of low-melting PP have solved the adhesion problem, but at somewhat higher cost.
Another problem has been the difficulty in removing air bubbles trapped between the label and package wall, causing unsightly blisters. Perforated labels are now available with invisibly small holes to let air escape.
Standard OPP labels have presented problems of excessive shrinkage due to the heat encountered in IML.

In Europe, where most of the IML activity is occurring, rectangular containers for ice cream and ready meals are the primary application segments, because IML is considered faster and less costly than offset printing. Meanwhile, round containers, which are more popular in the U.S., are still more economically decorated by offset printing. Besides different popularity of particular package shapes, global penetration of thermoforming IML will depend on the degree of exploitation of IML�s potential for eye-catching consumer appeal. Compared with the U.S., European packagers are said to place a greater emphasis on colorful graphics and decoration for product differentiation. Observers say this has been a driving force in the explosion of injection molding IML�where Europe also leads the U.S.�in place of printed thermoformed containers.

Most of the major machine suppliers offering IML systems say the technology is here and ready for market. But even with the current improvements in output, there still remains a gap versus the productivity of conventional thermoforming. IML slows down the process, reducing output to 20 cycles/min vs. 40 cycles/min for standard thermoforming of PP cups. Nearly all the machine systems for IML incorporate tilting-mold technology, which provides greater accessibility and easier label placement.