Secondary printing and processing of self-adhesive labels is mainly applied to small labeling equipment with simple structures and few functions. Generally, high-end intermittent self-adhesive label paper feeding equipment is equipped with secondary printing and processing devices to expand its functions. Rotary label machines, on the other hand, have more functions and can combine and change printing specifications, so more complex labels can be completed in a single processing.

Self-adhesive labels require secondary printing and processing in the following cases:
① To increase the number of printing colors. Intermittent label machines (flat bed on flat bed, cylinder on flat bed) are limited by the structure of the glue roller and can print a maximum of four colors. If the label requires more than five colors, it must be printed twice: first four colors are printed, and then other colors are printed in a second run.
② To enlarge the printing area. The paper feeding width of intermittent label machines is fixed. To enlarge the printing area of the label, a large-area glue roller must be used (machines generally have four-color, three-color, and two-color glue rollers). Increasing the inked area of the roller reduces the number of colors on the roller. Therefore, to ensure large-area label printing, secondary or multiple printings are required.
③ To expand equipment functions. Some simple label equipment has limited functions. For example, hot stamping, die-cutting, and punching share the same platform. To meet the various processing needs of labels, the roll paper needs to be processed on the same workstation two or more times to complete the entire label printing.
④ To ensure quality and reduce waste. Multi-functional self-adhesive label equipment often also adopts secondary processing methods to ensure quality and reduce consumption. Because rotary machines have multiple functions, any problem in a single procedure can cause label waste during printing. Therefore, some printing factories use the method of printing first and then processing, running the roll paper through the machine twice (either on the same machine or on two machines) to ensure label printing quality. Although production efficiency decreases, overall consumption is reduced, ensuring quality and lowering costs.