Swapping plastic clamshells and shrink film for compostable bags, boxes, and wraps is one of the fastest ways a bakery can cut its environmental footprint and back up its “sustainable” branding with something customers can actually see and feel. But not all packaging labeled “eco-friendly” behaves the same way once it leaves your counter, and picking the wrong material for the wrong product can mean soggy croissants, ripped bags, or packaging that quietly ends up in a landfill instead of a compost pile.
This guide walks through the main compostable materials bakeries use today — kraft paper, PLA-lined film, glassine, and molded fiber — what certifications actually mean, and which format fits which product, so you can make the switch without guessing.
Quick Answer
For most bakeries, the best mix is uncoated kraft paper bags for bread and rolls, glassine or PLA-windowed kraft bags for pastries and cookies, and molded fiber (bagasse) or coated-paperboard boxes for cakes and larger items. Look for BPI certification (ASTM D6400 for plastics, D6868 for coated paper) if the packaging needs to go to industrial composting, since most compostable plastic-lined items will not break down in a home compost bin.
The Main Compostable Materials, Compared
Uncoated kraft paper is the workhorse of bakery packaging: it’s inexpensive, widely available, recyclable if kept clean and dry, and compostable in both home and industrial systems since it has no plastic coating. Its porous structure lets steam escape, which is exactly what you want for bread and rolls — sealing warm bread in plastic traps moisture and speeds up mold. The tradeoff is that plain kraft paper offers little grease or moisture barrier, so it’s a poor match for anything oily or wet unless it’s paired with a liner.
PLA (polylactic acid) is a corn-starch-derived plastic used for clear windows in bags and boxes, clamshells for pastries, and cold-drink cups. It looks and performs like conventional clear plastic, which is great for showing off decorated cakes or laminated pastries, but it is industrially compostable only — it needs the sustained heat of a commercial composting facility to break down, and it will not decompose in a backyard compost pile or a landfill any faster than regular plastic. If your area lacks industrial composting access, a PLA window mostly just adds recycling confusion, since PLA is not accepted in most curbside plastic recycling either.
Glassine is a smooth, semi-translucent, greaseproof paper made by super-calendering pulp under heat and pressure, with no wax or plastic coating added. That makes it naturally compostable and recyclable while still resisting grease and oil, which is why it’s a longtime favorite for interleaving cookies, wrapping individual pastries, and lining bakery boxes. It costs more than plain kraft paper but less than most plastic-lined alternatives.
Molded fiber, usually made from bagasse (sugarcane pulp), bamboo, wheat straw, or recycled paper, is the go-to for rigid trays, clamshells, and cake bases. It’s sturdy enough to support heavier baked goods, holds up reasonably well to grease and moisture without a plastic liner, and is both home- and industrially compostable in its unlined form. Some molded fiber products add a thin compostable coating for extra moisture resistance — check the certification to confirm the coating is compostable and not a standard plastic laminate.
Matching Packaging to Product
Bread and rolls: plain or waxed-free kraft paper bags let steam escape and stay crisp longer than plastic. Avoid fully sealed plastic bags for anything with a crust.
Pastries and croissants: a glassine liner or bag keeps butter and oil from soaking through while staying compostable; pair with a kraft paper bag or box for structure.
Cookies and bars: glassine sheets for interleaving, plus a kraft or molded-fiber box for the outer container.
Cakes and larger items: molded fiber boxes or trays, or coated paperboard boxes certified under ASTM D6868, provide the rigidity plastic clamshells used to offer without the plastic.
Take-out sandwiches and savory items: PLA-lined kraft bags or glassine give some grease resistance while remaining compostable, though they typically need industrial composting to break down.
Tips / Common Mistakes
Don’t assume ‘compostable’ means ‘home compostable.’ Most PLA-based and plastic-coated compostable packaging is rated for industrial composting facilities only, which reach higher, sustained temperatures than a backyard bin. If your city or region doesn’t offer industrial/commercial composting pickup, that packaging will most likely end up in the trash regardless of the label — plain kraft paper, glassine, and unlined molded fiber are safer bets for areas without composting infrastructure.
Check for real certification, not just marketing language. Look for the BPI (Biodegradable Products Institute) certification mark, or references to ASTM D6400 (compostable plastics) and ASTM D6868 (compostable coatings on paper/fiber), or the TÜV Austria “OK Compost” mark for products sold internationally. A green leaf logo or the word “eco” printed on a bag isn’t a certification, and in the U.S. any “biodegradable” or “compostable” claim a supplier makes is also subject to FTC truth-in-advertising rules, so it’s fair to ask a supplier what evidence backs their labeling.
Don’t seal moist or warm baked goods in plastic-free packaging without a barrier layer — plain kraft paper wicks and holds grease, which can weaken the paper and stain it. Use a glassine liner or wax-free grease-resistant kraft for anything oily.
Test before switching your whole line. Order samples of bags and boxes and run them through a real day of packing warm bread, iced pastries, and boxed cakes before committing to a bulk order — moisture and grease behave differently under fluorescent store lighting than in a supplier’s product photos.
Ask your composting hauler what they’ll actually accept. Some municipal or commercial composters reject packaging with any plastic content, even certified compostable plastic, because it’s hard to visually distinguish from non-compostable plastic on their sorting line.
Explore more: more sustainable packaging guides.
Sustainable bakery packaging FAQs
Is compostable bakery packaging more expensive than plastic?
Generally yes, especially for PLA-lined or molded fiber items, though the gap has narrowed as demand has grown. Plain kraft paper bags are often close in price to plastic bags, while certified compostable boxes and clamshells typically cost more per unit than their plastic equivalents.
Can I compost bakery packaging in my backyard compost bin?
Only if it’s uncoated — plain kraft paper, glassine, and unlined molded fiber (bagasse) typically break down in a home compost pile. Anything with a PLA lining, window, or coating usually needs an industrial composting facility that reaches higher sustained temperatures.
What’s the difference between BPI certified and just labeling something ‘biodegradable’?
In the U.S., ‘biodegradable’ claims are governed by the FTC’s Green Guides, which require a company to have evidence that the product will break down completely into natural elements within about a year under normal disposal before it can use an unqualified ‘biodegradable’ claim — so it isn’t a free-for-all marketing term, but it’s also self-reported and not independently verified. BPI certification goes further: it’s a third-party audit confirming the product meets the ASTM D6400 or D6868 standard and will compost in an industrial facility within a defined timeframe, which is a stronger guarantee than a biodegradable label alone.
Will compostable packaging keep bread and pastries fresh as long as plastic?
It depends on the product. Porous kraft paper is actually better than plastic for crusty bread because it lets moisture escape, but it offers less freshness retention for items like sliced sandwich bread. Glassine and grease-resistant kraft close some of that gap for pastries.
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Photo by Bas Peperzak on Unsplash.