When to pick CUK
Pick CUK when you need brown-core strength, moisture resistance, and a coated white printable face. Beer and soft drink multipacks, frozen food cartons in direct freezer contact, and heavy-duty merchandise packaging all use CUK.
When to pick FBB
Pick FBB when the carton needs a bright white appearance, premium print, and light-to-medium weight contents. Cosmetics, pharma, and confectionery cartons dominate the FBB market.
The decision in one paragraph
If the carton needs strength and moisture resistance above print perfection, CUK. If the carton needs premium visual appearance for a consumer-goods shelf, FBB.
Frequently asked questions
What does CUK stand for?
Coated unbleached kraft. Sometimes called SUS in the US market or CKB in ISO 15755.
Is CUK recyclable?
Yes. CUK enters the recovered paper stream and is repulped into cartonboard or containerboard. PE-coated CUK requires separation of the PE layer before repulping, which some mills cannot handle.
Why is CUK cheaper than FBB?
CUK avoids the bleaching step, which cuts chemical cost. Unbleached fiber is also generally cheaper than bleached.