Pass Order Decides Which Effects Remain Achievable
Pass order determines surface energy, registration accuracy, recyclability, and unit scrap rates across multi-step print converting runs.
Registration Tolerance
Print Alignment Standard
Spatial deviation boundaries define the maximum allowable physical displacement between successive ink layers, die-cut paths, foil impressions, and fold lines on a converted packaging substrate. Expressed in fractions of a millimeter or thousandths of an inch, registration tolerance sets the acceptable boundary within which all graphic and structural elements must align. Printing presses and converting equipment encounter web tension shifts, paperboard hygroexpansion, mechanical gear backlash, and plate mounting variations during production runs.
Quality control protocols evaluate print-to-print, print-to-cut, and print-to-emboss accuracy against agreed customer specifications and structural converting limits. Tighter alignment tolerances demand stable environmental pressroom controls, precision tooling, and automated optical register inspection systems.
Alignment Variation Factors
Multicolored offset and flexographic printing passes lay down individual ink separations that must overlap with spatial accuracy, governed by dedicated register marks and optical tracking cameras. Substrates undergo moisture loss or absorption during inter-station UV curing and hot-air drying, inducing dimensional expansion or contraction across the cross-direction paper web. A standard folding carton specification permits a print-to-print deviation within zero-point-one millimeters, whereas print-to-die-cut tolerances range between zero-point-five and one-point-zero millimeters.
Automatic register systems adjust cylinder phase and lateral plate positioning dynamically during high-speed runs to counteract mechanical drift and substrate stretching. Trapping techniques expand neighboring color boundaries by fractions of a point to visually hide minor alignment shifts that remain within allowable technical tolerances.
Tolerance Parameter Boundary
Color density shifts, dot gain variations, and spectral delta-E color discrepancies fall outside the scope of physical registration alignment parameters. Sheet-to-sheet feeding skew that does not alter internal graphic-to-cut relationships belongs to gross feeder alignment categories rather than separation register. Registration parameters do not measure structural board caliper, basis weight variance, or absolute moisture percentages.
Variations exceeding contractual registration tolerances result in misaligned graphics, exposed white gaps between solid color traps, or off-center die-cut borders, triggering lot rejection. Mechanical registration limits stop applying when converting unprinted raw paperboard reels into plain unprinted carton blanks.