Paper Cup Stock Grades Explained: How to Choose

September 14, 2026 · Reading time: 4 min

If you make or buy paper cups, the most important raw material decision is the cup stock — the food-grade paperboard that becomes the cup wall. Here is a plain-language guide to the grades available and how to pick.

What is cup stock?

Cup stock is a single-side coated, food-contact paperboard made from wood pulp. It must pass food-safety standards (e.g. GB 4806.8 in China, EU and US FDA rules for export) and resist liquid edge-wicking so the cup does not leak or soften.

Common cup stock grades

• Standard cup stock (FK2 class) — 210–320 gsm, the everyday grade for vending and takeaway cups.
• Premium cup stock (FK1 class) — 190–320 gsm with higher stiffness and whiteness for printed branded cups.
• High-bulk cup stock (FKO) — 170–210 gsm; lighter weight with extra thickness, saving pulp cost while keeping cup rigidity.
• Foam-cup stock (FKK) — 280–300 gsm for insulated/foam-embossed cups.
• Barrier-coated cup stock — PE/PLA pre-coated or zero-plastic (EPP) options for hot or cold drinks without a separate lamination step.

How to choose grammage

• 6–9 oz cups → 170–210 gsm (high-bulk saves cost)
• 12–16 oz cups → 210–250 gsm
• Large / hot drinks → 280–320 gsm or barrier-coated

What to check before ordering

• Edge wicking / water penetration (≤ 5 mm after 30 min is typical for good stock)
• Food-contact certificates (GB 4806.8, FDA, EU 1935/2004)
• Whiteness and printability for your branding
• Lamination compatibility: PE or PLA