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Crease retention refers to paper’s ability to maintain sharp, stable folded creases without rebound or flattening, a critical performance indicator for folding cartons, invitation paper, cosmetic packaging and luxury printed inserts. Many high-grade paper products suffer from crease rebound after die-cutting and folding, where pre-pressed creases gradually spring back flat during storage and transportation. This defect causes packaging boxes to lose three-dimensional shaping effect, resulting in loose assembly, deformed packaging outlines and degraded brand presentation. The root causes include excessive fiber elasticity, insufficient localized compression density, unstable inter-fiber bonding at crease lines and uneven moisture distribution along folding tracks. Most conventional crease optimization methods only increase creasing pressure during die-cutting, which easily crushes internal fibers to cause crease cracking, while light pressure cannot lock crease shape effectively. Softening agents used for crease improvement often reduce paper surface stiffness, damaging the overall shaping performance of finished packaging. Shandong Ludao Energy Technology Co., Ltd. launches professional crease retention optimization solutions. By enhancing localized fiber compactness at crease zones, locking compressed fiber structure and regulating micro-moisture balance along folding lines, we permanently fix folded creases without internal fiber crushing. The treated paper delivers sharp creases with zero rebound, maintains long-term stereoscopic shaping effect after folding, avoids box deformation and assembly failure, perfectly fits luxury customized packaging, and improves the high-end texture of finished paper products.