How to Choose the Right Paperboard and Paper Weight (GSM & Caliper)

Q1: What is the difference between C1S and C2S paperboard?

C1S (Coated One Side) has a smooth, glossy coating on the exterior for sharp printing, leaving the inside raw. C2S (Coated Two Sides) is coated on both sides, allowing high-graphics offset printing inside and outside the box.

Q2: What does CCNB paperboard mean, and where is it used?

CCNB (Clay Coated News Back) is a recycled paperboard with a smooth white clay-coated front and a grey recycled back. It is a cost-effective material option for food retail cartons and secondary packaging.

Q3: Which corrugated flute thickness is best for mailing heavy items?

For standard e-commerce shipping, E-Flute (~1.5mm) offers the best print quality and structural balance. For heavier products exceeding 5kg, B-Flute (~3.0mm) or EB Double-Wall Flute (~4.5mm) provides superior stacking strength.

Q4: How does humidity affect paperboard stiffness?

Paper fibers absorb ambient atmospheric moisture. Without protective surface film lamination (Matte or Gloss PE film), unlaminated paperboard can soften and lose structural rigidity in humid ocean shipping environments.

Q5: Can I request FSC-certified virgin paperboard for my custom boxes?

Yes. Gerun Packaging supplies FSC (Forest Stewardship Council) certified paperboard options, ensuring wood pulp originates from responsibly managed, sustainable forests with chain-of-custody documentation.