Most cafes don't get their bag sizing wrong because nobody thought about it — they get it wrong because the decision gets made once, early on, and never revisited as the menu grows. A size that worked for a simple sandwich-and-coffee counter starts falling short the moment burgers, salad bowls, or delivery orders enter the mix. The result is staff improvising with whatever's closest to hand: too much bag for a muffin, not enough for a stacked lunch order.
This guide isn't a container-by-container measuring exercise. It's a practical framework for deciding what to stock, how many sizes you actually need, and when it's worth introducing a specialised format like glassine or a reinforced SOS base — so your ordering decisions hold up as your counter gets busier.
The Three Bag Formats, and When Each One Earns Its Place
Before sizing anything, it's worth being clear on format, because the wrong format causes more friction than the wrong size.
Flat bags are the simplest option — an open-top bag with no standing base. They're fast to load and cheap to stock, which makes them the right default for sandwiches, wraps, and pastries that don't need to stand upright.
SOS (Self-Opening Sack) bags have a reinforced gusseted base that lets them stand on their own the moment they're opened. This matters most during rush periods, when staff don't have a spare hand to hold a bag open while loading a container. If your counter does high volume during a lunch window, the seconds saved per order on an SOS format add up quickly.
Handled kraft bags add twisted or flat handles, which changes the customer's experience more than the staff's. They're worth the extra cost when orders are heavier, when customers are walking further to their car or a table, or when the bag itself is doing double duty as part of your brand presentation.
A useful rule: pick the format based on how the bag will be carried and loaded, then pick the size based on what's going inside it.
A Faster Way to Size Your Own Containers
Rather than working from generic container categories, measure what's actually on your counter right now:
- Pull your three or four most-ordered containers — whatever combination of container plus wrapping goes out most often.
- Stand each one on its base and note the widest point across the bottom. This is the number that matters most; it determines whether the container will sit flat rather than wedge sideways.
- Add roughly 15–20mm of clearance to that width. This accounts for a napkin, a sauce cup, or a slightly imperfect pack job without needing a size up.
- Check the height last. The item should sit at least 30–40mm below the top of the bag before folding or handle attachment — anything less and the bag will look overstuffed even if it technically fits.
Do this once for your top few sellers and you'll usually find two, maybe three sizes cover the vast majority of your counter — which is the actual goal, not finding the "correct" bag for every SKU in isolation.
Sizing by Order Type, Not Just Food Type
Grouping by how the order leaves the counter is often more useful than grouping by food category, since the same dish can need different bags depending on what it's paired with.
The solo grab-and-go order — a single pastry, a wrapped sandwich, one drink. This is where a well-fitted small bag or a glassine bag actually improves presentation, because there's no wasted space for the item to shift around in. Oversizing here is the most common — and most avoidable — cost leak on a counter.
The single hot meal — one main container, maybe a side. This is the highest-volume category for most cafes and deserves a dedicated mid-size bag rather than being squeezed into your smallest option or padded out in your largest.
The stacked or multi-container order — two or more containers, a drink carrier, or a combination of mains and sides. These need a bag chosen for gusset width first and height second, since the failure mode here is containers tipping sideways against each other rather than the bag being too short.
The bakery or catering box order — trays, multiple pastries boxed together, or event-style orders. These are infrequent enough that many cafes don't stock a dedicated size and instead improvise with a doubled-up bag, which is usually a false economy once you account for torn bags and re-packed orders.
Paper Weight: The Variable Cafes Forget to Check
Size gets the attention, but paper weight (GSM) is what actually determines whether a bag survives the trip to the table or the car. As a rough guide:
- 50gsm is fine for light, dry items — a single pastry, a wrapped sandwich, anything that isn't generating condensation or carrying real weight.
- 70gsm is the safer default once you're bagging a filled hot meal container, anything with sauce, or two items together.
- 80gsm or higher is worth the extra cost for multi-container or catering-style orders, where the combined weight of several containers puts real strain on the base and handles.
A bag that's the right dimensions but the wrong weight will still fail — usually at the worst possible moment, mid-handover.
When Standard Kraft Isn't the Right Material
Grease and moisture behave differently to weight, and they call for a different bag material rather than just a heavier paper. Glassine — a smooth, grease-resistant paper — is the better choice for pastries with butter content, fried items, and anything else that would otherwise leave oil marks through standard kraft within minutes. It's a small swap that keeps your branding legible and your bags from going translucent on the counter before the customer even leaves.
A simple test: if you're regularly seeing grease spots on your current bags, that's a material problem, not a sizing one — no amount of upsizing the bag will fix it.
Building a Lean Bag Range Instead of a Sprawling One
The most efficient cafes typically run on three to five bag SKUs total, not the dozen-plus options a full supplier catalogue might suggest. A workable range usually looks like:
- One small format (flat or glassine) for solo grab-and-go items
- One mid-size SOS or handled bag for single hot meals
- One larger format for stacked or multi-container orders
- A glassine option if grease-prone items make up a meaningful share of your menu
Adding sizes beyond this rarely improves the customer experience — it mostly adds SKUs for staff to remember and stock to store. If you're regularly reaching for a size once or twice a week rather than daily, it's worth asking whether that order type could be absorbed into an existing size with a bit of extra clearance instead.
Where Sustainability Fits Into the Decision
Australian customers increasingly notice packaging choices, and it's become a reasonable factor in supplier selection rather than a niche add-on. Recyclable and compostable paper options are now widely available across most of the formats covered above, so sustainability doesn't have to come at the expense of getting the sizing and material right — it's worth treating as one more column in the same decision, not a separate one.
Frequently Asked Questions
How many bag sizes should a cafe actually stock? Most cafes cover their full menu comfortably with three to five sizes across formats. More than that usually reflects reactive ordering rather than a planned range.
Should I size bags around my busiest order or my average order? Around your busiest common order — not your rare catering order, and not your smallest single item. Outliers are better served by a dedicated bag used occasionally than by resizing your whole range around them.
Is it worth using SOS bags if my counter isn't high-volume? Not necessarily. The main benefit of SOS bags is speed during loading, which matters most under time pressure. If your counter isn't consistently busy, a flat or handled bag may be cheaper without costing you anything operationally.
How do I know if I need to move up a paper weight? If bags are tearing at the base or handles, sagging under a filled container, or showing grease through within minutes of packing, that's a signal to move up in GSM or switch to a grease-resistant material — not just to size up.
Does bag choice really affect cost, or is it a minor line item? It adds up faster than most cafes expect, mainly through oversized bags used by default and torn bags from the wrong paper weight. Auditing your actual order mix once and adjusting your range accordingly is usually a quick win rather than a major project.