Virgin SBS against White Lined Chipboard for Retail Facings
Virgin SBS provides superior print brightness, stiffness consistency, and crack-free scoring, whereas recycled board lowers initial cost but adds waste.
Press Speed Picking Limits
Printing Velocity
Maximum printing press operational speeds achievable before high-viscosity ink film splitting forces pull fibers or coating fragments from a paper surface establish press productivity thresholds. Press speed picking limits mark the threshold where ink surface tack overcomes the internal bond or surface sizing strength of paperboard substrates. Exceeding this velocity causes surface picking, linting, and blanket contamination during offset printing runs.
The boundary ceases to govern non-contact printing processes such as inkjet printing.
Surface Tack
High-speed offset printing subjects paper surfaces to intense shear stress as wet ink films split between printing blankets and moving paper webs. Exceeding press speed picking limits results in coating delamination or fiber pick-out, leaving white spots on printed images and requiring frequent blanket washing downtime. Ink tack increases with press speed and decreases as ink temperature rises during extended production runs.
Paper mills apply surface starch sizing and adjust binder ratios in coating formulations to enhance pick resistance. Ink formulations incorporate tack reducers or solvents to permit higher press throughput without compromising print contrast. Printers perform IGT pick resistance tests on paper stock to determine maximum safe press speeds before loading job lots.
Balancing ink viscosity against paper surface strength maintains print cleanability and press efficiency.
Operational Ceiling
Ink temperature, press dampening chemistry, and paper surface temperature alter surface strength dynamics during active printing runs. Establishing press speed picking limits requires standardized IGT or Dennison wax testing under laboratory climate conditions. Low surface strength packaging board forces press operators to run equipment below rated mechanical speeds, increasing unit production costs.
The limit becomes irrelevant when using low-tack flexographic or digital ink systems.