The manufacturer of the packaging often called upon to supply a paper mock-up which is realistic of the final package and the design there on.
At this stage (prior to producing printing plates) designer is able to confirm the look of the product, positioning of elements, and sizing.
Raised Image supply digitally printed proof for mock-ups. The pictures are generally 95% indicative of the final print, and spot colour pantones are specified. Generally, a mock-up can assist in creativity, provide an attractive visualisation, and allow for final text positioning in the simplest manner.