Q1: What is the core purpose of applying an inline primer, and when is it necessary?
A: Its core purpose is to functionally prepare and seal the substrate surface in-line, before the main printing units. It is necessary for achieving optimal results on porous, uncoated, or uneven stocks, and when applying specialty inks or demanding topcoats (like UV or foil) that require a perfectly sealed and receptive base for maximum adhesion and performance.

Q2: What are the key benefits for print quality and production efficiency?
A: It provides three key benefits: 1) Enhanced Print Quality: Improves ink holdout for sharper dots, richer color density, and superior gloss. 2) Increased Production Efficiency: Enables high-quality printing on lower-cost or challenging substrates in a single pass, reducing waste and offline pre-treatment steps. 3) Improved Compatibility: Creates a stable base that enhances the success rate of subsequent finishing processes.

Q3: Are there specific application guidelines regarding drying and sequence on press?
A: Yes. It must be applied in the first coating unit before the ink units. Complete drying via the press's infrared (IR) and/or hot-air dryers before the sheet reaches the first printing unit is critical to prevent back-trapping of ink into the primer and to ensure proper surface energy. A test run to determine optimal coating weight for your specific substrate is essential.