Understanding Paperboard Caliper Points & Basis Weight
In professional packaging engineering, paperboard caliper is measured in points (where 1 pt = 0.001 inches). Selecting between Solid Bleached Sulfate (SBS) and Coated One-Side (C1S) directly determines structural integrity, hinge fatigue resistance, and retail presentation.
SBS paperboard represents virgin hardwood and softwood pulp fiber bleached white throughout the substrate. Because both sides of the sheet are solid bleached, it provides exceptional brightness (88–92 GE) and zero gray recycled inclusions, making it mandatory for pharmaceutical, cosmetic, and food packaging under FDA 21 CFR 176.170.
Taber Stiffness & Grain Direction Tolerances
A carton's crush resistance depends critically on fiber alignment. Paper fibers align predominantly in the machine direction (MD). Creasing across the grain (cross-direction or CD) yields a crisp, rigid corner fold, whereas scoring parallel to the grain risks bulging or split creases.
For retail folding cartons holding bottles over 4 oz (such as 30ml–60ml tincture or cosmetic creams), a minimum caliper of 18pt to 20pt SBS is recommended to prevent carton bowing under stacking pressure.
100 MOQ Wholesale Production & $0 CAD Dieline Setup
At XCB Packaging, custom SBS and C1S folding cartons are engineered factory-direct with a 100 MOQ Wholesale Production threshold. DTC brands receive full structural CAD dielines with exact grain direction markers and a Free 24h 3D Digital Proof before physical tooling.
⚡ Engineering Specifications
| Substrate Type | Solid Bleached Sulfate (SBS) Virgin Board |
|---|---|
| Available Calipers | 14pt (0.014 in), 16pt (0.016 in), 18pt (0.018 in), 24pt (0.024 in) |
| Brightness Rating | 90 GE Brightness, 100% Solid White Core |
| Production MOQ | 100 Units Wholesale Short-Run |
| Prepress Dielines | 300 DPI Vector PDF / AI with 0.125 in Bleed Clearance |
Frequently Asked Questions
C1S (Coated One Side) has a clay-coated printable exterior with a natural or unbleached interior. SBS (Solid Bleached Sulfate) is 100% bleached virgin fiber throughout both sides, providing a clean white aesthetic inside and out.
18pt SBS (approx. 350 GSM) is the industry standard for cosmetics, providing crisp creasing, zero corner blowout, and high tactile rigidity.