A Rotterdam food truck owner sent us six photos last spring: same white paper lunch bags, same fried chicken, same ten minutes. Four showed dark patches at the base, two were fine. The variable was the gsm, and which side the glue landed on. White paper lunch bags look simple. They are the product we get the most complaints about per thousand pieces.
White kraft, bleached paper and the grey area in between
Bleached kraft is pulp whitened through, typically 80-90% ISO brightness, so a folded or torn edge stays white.
White-top duplex is recycled board with a thin white coating on one face. Cheaper, stiffer, grey inside.
Unbleached off-white “natural” kraft sits at 70-78% ISO, cream in daylight and ivory under warm LED. Tell your supplier which one in writing: the words “white kraft” on a PO has cost buyers a container of mismatch.
GSM and what actually loads the bag
Load capacity is not one number. A flat bag’s bottom fold is a weak line, so it holds less per gram of paper.
| Bag style | Typical gsm | Realistic load | Notes |
|---|---|---|---|
| Flat bag, 18 x 22 cm | 40-50 | 300-400 g | Pastry |
| Flat bag, 25 x 35 cm | 50-60 | 600-900 g | Sandwich |
| Square bottom, 20 x 10 x 30 cm | 60-70 | 1.0-1.5 kg | Fries, burger |
| Square bottom, 26 x 12 x 35 cm | 70-90 | 1.8-2.5 kg | Family takeaway |
Two rules from our line: above 60 gsm a flat bag’s value falls off, because a square bottom bag at the same weight is stronger and stacks better. If the bag hangs from a handle, stay at 70 gsm or above. Pair it with matching cup weights – see our single wall paper cups for the usual pairings.
Grease-through: the part nobody quotes for
Paper is a sponge. A 50 gsm flat bag with no barrier shows a patch on the base within 8-15 minutes at 60-70 °C. It may hold, but looks like a leak in a photo.
Our test drops 5 ml of sunflower oil at 70 °C on the inner face and checks the outer face. Uncoated 60 gsm kraft breaks through in 10-20 minutes; a 10-12 gsm PE-free water-based barrier holds 45-70 minutes; a greaseproof laminate runs two hours and beyond.
A good barrier adds USD 0.008-0.02 per bag at 50,000 pieces. Fluorinated barriers bring a second problem: PFAS rules are tightening in the US and EU, so buyers now ask for a PFAS-free declaration alongside the food-contact pack. We default to non-fluorinated barriers.
Flat versus square bottom, and the window question
A flat bag is one sheet and one bottom fold, the cheapest thing to print, and it cannot stand up. A square bottom bag has a separate panel glued at four flaps: more paper, more labour, roughly 15-25% higher unit cost at the same gsm, but it stands on a counter. For food trucks it wins almost every time; for a bakery handing over one pastry, flat is enough. A BOPP film window shows the product but rules the bag out of paper recycling; a greaseproof paper window stays mono-material but fogs.
Printing cost against MOQ
| Volume, 1 colour | Plate + set-up | Print add per bag |
|---|---|---|
| 10,000 | USD 180-260 | USD 0.006-0.010 |
| 30,000 | USD 180-260 | USD 0.003-0.005 |
| 100,000 | USD 180-260 | USD 0.001-0.003 |
Most white lunch bags are flexo printed in one or two water-based colours. Plate and make-ready cost dominates, not ink. Below 10,000 pieces, unprinted bags plus a sticker usually beat one-colour flexo – we say so even when it costs us a print job. Flexo MOQ: 10,000 pieces per size.
Carton counts and freight cube
- Flat 25 x 35 cm, 50 gsm: 5,000 per carton, about 0.055 cbm
- Square bottom 20 x 10 x 30 cm, 70 gsm: 500 per carton, about 0.065 cbm
- A 40 HQ holds 55-62 cbm usable
Flat bags compress; square bottom bags do not. 500,000 flat bags is about 5.5 cbm, against 65 cbm for square bottom. Sea freight to the US West Coast ran USD 4,500-8,500 per 40 HQ in 2024-25, to Rotterdam USD 2,800-5,000.
Food-contact paperwork, market by market
United States: FDA 21 CFR 176.170 covers paper and paperboard components of food-contact articles; 21 CFR 176.180 covers dry-food contact. You need the mill’s and coaters’ declarations for both.
European Union: framework Regulation (EC) 1935/2004 plus GMP Regulation (EC) 2023/2006, with a declaration of compliance and migration test data. On top sit Germany’s BfR Recommendation XXXVI for paper and board, and Italy’s DM 21/03/73.
The fibre is rarely the problem. The ink, the bottom-seam adhesive and the barrier coating are. Ask for the declaration to name all three, with a date. We issue a combined pack per SKU, as we do for our bagasse clamshell lunch boxes.
What we quote, and what we refuse to quote
- Flat, 25 x 35 cm, 50 gsm bleached kraft, unprinted: USD 0.021-0.030
- 1 colour flexo: USD 0.026-0.036
- Square bottom, 20 x 10 x 30 cm, 70 gsm, grease barrier, 1 colour: USD 0.052-0.075
- Window square bottom, paper film, 2 colours: USD 0.068-0.095
FOB Qingdao at 30,000 pieces, 15-22 days production after artwork approval plus 25-32 days by sea to Europe. We will not quote 40 gsm for fried food or put a compostable logo on a poly-lined bag. Send bag size, food type, hold time and market for two options. Start at our contact page or browse our paper bag wholesale range.
FAQ
Are white paper lunch bags food safe?
Only if paper, ink and adhesive all carry declarations for your market. The risk sits in coatings and printing, not fibre colour: ask for FDA 21 CFR 176.170 or a 1935/2004 declaration.
Do I need a greaseproof lining for chips or fried chicken?
For anything fried and served above 60 °C with a hold time over 15 minutes, yes. Uncoated 60 gsm kraft shows oil patches within 20 minutes; a non-fluorinated barrier reaches 45-70 minutes.
What gsm is best for a takeaway lunch bag?
50-60 gsm for a flat bag carrying a sandwich or pastry, 70-90 gsm for a square bottom bag carrying 1-2.5 kg. Below 50 gsm the bag creases and the bottom seam fails.
Is a window worth it on a white lunch bag?
A greaseproof paper window suits bakery and keeps the bag recyclable; BOPP film is clearer but rules out paper recycling.
Can I print fewer than 10,000 bags?
Yes. Above 10,000 pieces flexo is cheap; under it, unprinted bags plus a label usually win, and we quote both so you can see it.
Do white bags cost more than brown kraft?
Typically 8-15% more at the same gsm, because bleached pulp costs more and whiteness must hold lot to lot.
