Pick a cake cup by the peak bake temperature and the fat it must keep off the tray, not by the cup's width. A 45 mm fluted cup at 230 °C scorches and halos like any thin grade; a heavy barrier grade under a 150 °C sponge is money you did not need to spend.
What a cake cup has to do in the oven
A cake cup is a thin paper wall doing four duties: keeping the mix off bare metal, holding shape while the sponge firms, letting the baked crumb drop out whole, and staying food-contact at the temperature it meets. A 50 mm cup has a high wall-to-volume ratio: the paper takes oven heat on one face and mix on the other, and the flutes go first.
Fat is the other half. It migrates outward as the mix firms, and a bare grade wicks it into the wall — the translucent halo on a finished cup. A lean sponge gives up nothing; a butter-heavy or chocolate mix pushes a great deal.
Format matters as much as grade. Round, square, roll-rim and flat-bottom cups seat differently in a tray: a square cup braces its corners against the pocket wall, a roll-rim cup grips a flat tray by its lip, a flat-bottom cup stands on its own base. Flute depth and wall weight drift between lots, so batch-to-batch consistency of the cup wall belongs in the written grade.
Reading grammage against peak temperature
Buy cup paper with bands you can audit, not adjectives. Four values carry the decision, each with a method.
- Paper weight (gsm). Governs how the flutes crease, whether the wall stands free of a ring, and how much fat it absorbs before showing through.
- Peak bake temperature. The hottest point your oven reaches, plus the dwell time there — a 30-second flash and a half-hour hold are different demands.
- Grease barrier. None, a silicone-coated face, or a grade that blocks fat through its own fibre — a scored result, not an "anti-oil" claim.
- Cup format. Base width, wall height, flute count and opening style, each with a tolerance.
Reference bands to ask for — read each as a baseline, then verify by batch test on your mix and oven:
- Weight: 40–60 gsm for small fluted cups; 60–90 gsm where the cup stands free or carries a dense mix.
- Peak temperature: the ≤160 °C, 180 °C and 220 °C+ bands, each with its test method.
A supplier who answers all four with methods is easier to audit than one leading with a brand.
Choosing by bake-temperature band
Read the table downward: the band fixes the barrier, then the weight, then the format.
| Bake band | Paper weight | Grease barrier | Cup format | Release behaviour |
|---|---|---|---|---|
| Low — ≤160 °C | 40–50 gsm | None to a thin silicone film; a full barrier earns nothing | Small single-wall fluted cup | Lifts clean on lean sponges; clings to high-sugar mixes |
| Mid — 180 °C | 50–70 gsm | Silicone coat, or a light barrier | Deeper fluted cup, or roll-rim baking cup paper | Even release on butter and chocolate mixes; wall stays opaque |
| Top — 220 °C+ | 70–90 gsm | A full barrier, or a thicker silicone film | Roll-rim or double-wall | Bottom stays pale with no halo; flutes keep their shape |
Bands overlap — a 175 °C bake falls between the first two rows and either grade can be right; fat load and dwell time settle it.
Common misuses and boundaries
- Specifying by width. Cup width tells you what fits your tray, not whether the paper lasts the bake.
- Buying a barrier grade for a cool bake. Below 160 °C the extra layer earns nothing and changes how the paper creases.
- Running a low-band cup at the top of the oven. The bottom darkens before the crumb firms and the wall shows a halo; the fix is a heavier barrier grade, not a slower oven.
- Expecting one grade to cover every format. A wet, high-heat bake poured into a lined tin fails by seepage and scorching, not by sticking — handled separately under Basque cheesecake paper.
- Skipping the food-contact declaration. Get in writing that the grade is cleared for direct food contact under your market's rule.
FAQ
Does cup width change the grade I should buy?
Only for handling and format. Weight and barrier follow the peak temperature and fat load — a small cup at the top of the oven still needs the heavier grade.
Is a silicone layer the same as a barrier grade?
No. A barrier comes from the paper's own fibre; a silicone layer adds a release face on top. Heat and fat settle it.
Can I run one cup grade across every product I sell?
If that list spans the low and top bands, no. Buy for the hottest item, then verify it on the coolest.
Why does my cup bottom darken before the crumb firms?
Often a thin, bare grade at a hot peak. More weight and a fat barrier slow the heat reaching the bottom, holding moisture until the crumb firms.
Browse the range
Small-format cup paper sits under cake cups and liners; the rest of the shelf, from oven to release, runs from baking and food paper.