Tone Value Increase Target Derivation for Uncoated Papers
Deriving uncoated paper TVI targets demands separating optical light scattering from capillary ink absorption using M1 spectral data to set inverse RIP curves.
Substrate Procurement Specification
Contractual Parameter
Technical purchasing document defines physical, optical, and mechanical performance requirements for paper or paperboard orders. Manufacturing parameters specify grammage, caliper, moisture content, stiffness, brightness, and surface roughness tolerances for substrate orders. Constructing a comprehensive substrate procurement specification binds paper mills and converting plants to explicit quality compliance standards.
Procurement managers use technical specifications to evaluate mill delivery batches against contracted quality criteria.
Technical Tolerance
Grammage tolerances typically mandate compliance within plus or minus five percent of target nominal weight per square metre. Caliper specifications enforce uniform thickness limits to prevent sheet feeder jams and misregistration on high-speed packaging lines. Optical parameters define acceptable ISO brightness, CIE whiteness, and opacity ranges under standard illuminants.
Mechanical requirements stipulate minimum burst strength, internal bond strength, and taber stiffness values across machine directions. Substrate procurement specification documents state acceptable roll diameter, core size, splice counts, and moisture content limits for web-fed presses. Packaging converters reject non-compliant material lots that fail specified physical testing protocols upon plant arrival.
Acceptance Limit
Overly rigid specification tolerances raise paper mill production costs and drive up raw material procurement prices. Vague tolerance definitions lead to supplier disputes when converting machinery fails to process off-spec substrate batches. Unmonitored environmental changes during transit alter paper moisture content beyond specified receiving limits.